1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/scopeDesc.hpp"
31 #include "compiler/compileBroker.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/linkResolver.hpp"
34 #include "interpreter/oopMapCache.hpp"
35 #include "jvmtifiles/jvmtiEnv.hpp"
36 #include "memory/gcLocker.inline.hpp"
37 #include "memory/metaspaceShared.hpp"
38 #include "memory/oopFactory.hpp"
39 #include "memory/universe.inline.hpp"
40 #include "oops/instanceKlass.hpp"
41 #include "oops/objArrayOop.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "oops/symbol.hpp"
44 #include "prims/jvm_misc.hpp"
45 #include "prims/jvmtiExport.hpp"
46 #include "prims/jvmtiThreadState.hpp"
47 #include "prims/privilegedStack.hpp"
48 #include "runtime/aprofiler.hpp"
49 #include "runtime/arguments.hpp"
50 #include "runtime/biasedLocking.hpp"
51 #include "runtime/deoptimization.hpp"
52 #include "runtime/fprofiler.hpp"
53 #include "runtime/frame.inline.hpp"
54 #include "runtime/init.hpp"
55 #include "runtime/interfaceSupport.hpp"
56 #include "runtime/java.hpp"
57 #include "runtime/javaCalls.hpp"
58 #include "runtime/jniPeriodicChecker.hpp"
59 #include "runtime/memprofiler.hpp"
60 #include "runtime/mutexLocker.hpp"
61 #include "runtime/objectMonitor.hpp"
62 #include "runtime/osThread.hpp"
63 #include "runtime/safepoint.hpp"
64 #include "runtime/sharedRuntime.hpp"
65 #include "runtime/statSampler.hpp"
66 #include "runtime/stubRoutines.hpp"
67 #include "runtime/task.hpp"
68 #include "runtime/thread.inline.hpp"
69 #include "runtime/threadCritical.hpp"
70 #include "runtime/threadLocalStorage.hpp"
71 #include "runtime/vframe.hpp"
72 #include "runtime/vframeArray.hpp"
73 #include "runtime/vframe_hp.hpp"
74 #include "runtime/vmThread.hpp"
75 #include "runtime/vm_operations.hpp"
76 #include "services/attachListener.hpp"
77 #include "services/management.hpp"
78 #include "services/memTracker.hpp"
79 #include "services/threadService.hpp"
80 #include "trace/tracing.hpp"
81 #include "trace/traceMacros.hpp"
82 #include "utilities/defaultStream.hpp"
83 #include "utilities/dtrace.hpp"
84 #include "utilities/events.hpp"
85 #include "utilities/preserveException.hpp"
86 #include "utilities/macros.hpp"
87 #ifdef TARGET_OS_FAMILY_linux
88 # include "os_linux.inline.hpp"
89 #endif
90 #ifdef TARGET_OS_FAMILY_solaris
91 # include "os_solaris.inline.hpp"
92 #endif
93 #ifdef TARGET_OS_FAMILY_windows
94 # include "os_windows.inline.hpp"
95 #endif
96 #ifdef TARGET_OS_FAMILY_bsd
97 # include "os_bsd.inline.hpp"
98 #endif
99 #if INCLUDE_ALL_GCS
100 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp"
101 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
102 #include "gc_implementation/parallelScavenge/pcTasks.hpp"
103 #endif // INCLUDE_ALL_GCS
104 #ifdef COMPILER1
105 #include "c1/c1_Compiler.hpp"
106 #endif
107 #ifdef COMPILER2
108 #include "opto/c2compiler.hpp"
109 #include "opto/idealGraphPrinter.hpp"
110 #endif
111
112 #ifdef DTRACE_ENABLED
113
114 // Only bother with this argument setup if dtrace is available
115
116 #ifndef USDT2
117 HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin);
118 HS_DTRACE_PROBE_DECL(hotspot, vm__init__end);
119 HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t,
120 intptr_t, intptr_t, bool);
121 HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t,
122 intptr_t, intptr_t, bool);
123
124 #define DTRACE_THREAD_PROBE(probe, javathread) \
125 { \
126 ResourceMark rm(this); \
127 int len = 0; \
128 const char* name = (javathread)->get_thread_name(); \
129 len = strlen(name); \
130 HS_DTRACE_PROBE5(hotspot, thread__##probe, \
131 name, len, \
132 java_lang_Thread::thread_id((javathread)->threadObj()), \
133 (javathread)->osthread()->thread_id(), \
134 java_lang_Thread::is_daemon((javathread)->threadObj())); \
135 }
136
137 #else /* USDT2 */
138
139 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_PROBE_START
140 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_PROBE_STOP
141
142 #define DTRACE_THREAD_PROBE(probe, javathread) \
143 { \
144 ResourceMark rm(this); \
145 int len = 0; \
146 const char* name = (javathread)->get_thread_name(); \
147 len = strlen(name); \
148 HOTSPOT_THREAD_PROBE_##probe( /* probe = start, stop */ \
149 (char *) name, len, \
150 java_lang_Thread::thread_id((javathread)->threadObj()), \
151 (uintptr_t) (javathread)->osthread()->thread_id(), \
152 java_lang_Thread::is_daemon((javathread)->threadObj())); \
153 }
154
155 #endif /* USDT2 */
156
157 #else // ndef DTRACE_ENABLED
158
159 #define DTRACE_THREAD_PROBE(probe, javathread)
160
161 #endif // ndef DTRACE_ENABLED
162
163
164 // Class hierarchy
165 // - Thread
166 // - VMThread
167 // - WatcherThread
168 // - ConcurrentMarkSweepThread
169 // - JavaThread
170 // - CompilerThread
171
172 // ======= Thread ========
173 // Support for forcing alignment of thread objects for biased locking
174 void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) {
175 if (UseBiasedLocking) {
176 const int alignment = markOopDesc::biased_lock_alignment;
177 size_t aligned_size = size + (alignment - sizeof(intptr_t));
178 void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC)
179 : AllocateHeap(aligned_size, flags, CURRENT_PC,
180 AllocFailStrategy::RETURN_NULL);
181 void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment);
182 assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
183 ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
184 "JavaThread alignment code overflowed allocated storage");
185 if (TraceBiasedLocking) {
186 if (aligned_addr != real_malloc_addr)
187 tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
188 real_malloc_addr, aligned_addr);
189 }
190 ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
191 return aligned_addr;
192 } else {
193 return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
194 : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
195 }
196 }
197
198 void Thread::operator delete(void* p) {
199 if (UseBiasedLocking) {
200 void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
201 FreeHeap(real_malloc_addr, mtThread);
202 } else {
203 FreeHeap(p, mtThread);
204 }
205 }
206
207
208 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
209 // JavaThread
210
211
212 Thread::Thread() {
213 // stack and get_thread
214 set_stack_base(NULL);
215 set_stack_size(0);
216 set_self_raw_id(0);
217 set_lgrp_id(-1);
218
219 // allocated data structures
220 set_osthread(NULL);
221 set_resource_area(new (mtThread)ResourceArea());
222 set_handle_area(new (mtThread) HandleArea(NULL));
223 set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, true));
224 set_active_handles(NULL);
225 set_free_handle_block(NULL);
226 set_last_handle_mark(NULL);
227
228 // This initial value ==> never claimed.
229 _oops_do_parity = 0;
230
231 // the handle mark links itself to last_handle_mark
232 new HandleMark(this);
233
234 // plain initialization
235 debug_only(_owned_locks = NULL;)
236 debug_only(_allow_allocation_count = 0;)
237 NOT_PRODUCT(_allow_safepoint_count = 0;)
238 NOT_PRODUCT(_skip_gcalot = false;)
239 CHECK_UNHANDLED_OOPS_ONLY(_gc_locked_out_count = 0;)
240 _jvmti_env_iteration_count = 0;
241 set_allocated_bytes(0);
242 _vm_operation_started_count = 0;
243 _vm_operation_completed_count = 0;
244 _current_pending_monitor = NULL;
245 _current_pending_monitor_is_from_java = true;
246 _current_waiting_monitor = NULL;
247 _num_nested_signal = 0;
248 omFreeList = NULL ;
249 omFreeCount = 0 ;
250 omFreeProvision = 32 ;
251 omInUseList = NULL ;
252 omInUseCount = 0 ;
253
254 #ifdef ASSERT
255 _visited_for_critical_count = false;
256 #endif
257
258 _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
259 _suspend_flags = 0;
260
261 // thread-specific hashCode stream generator state - Marsaglia shift-xor form
262 _hashStateX = os::random() ;
263 _hashStateY = 842502087 ;
264 _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ;
265 _hashStateW = 273326509 ;
266
267 _OnTrap = 0 ;
268 _schedctl = NULL ;
269 _Stalled = 0 ;
270 _TypeTag = 0x2BAD ;
271
272 // Many of the following fields are effectively final - immutable
273 // Note that nascent threads can't use the Native Monitor-Mutex
274 // construct until the _MutexEvent is initialized ...
275 // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
276 // we might instead use a stack of ParkEvents that we could provision on-demand.
277 // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
278 // and ::Release()
279 _ParkEvent = ParkEvent::Allocate (this) ;
280 _SleepEvent = ParkEvent::Allocate (this) ;
281 _MutexEvent = ParkEvent::Allocate (this) ;
282 _MuxEvent = ParkEvent::Allocate (this) ;
283
284 #ifdef CHECK_UNHANDLED_OOPS
285 if (CheckUnhandledOops) {
286 _unhandled_oops = new UnhandledOops(this);
287 }
288 #endif // CHECK_UNHANDLED_OOPS
289 #ifdef ASSERT
290 if (UseBiasedLocking) {
291 assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
292 assert(this == _real_malloc_address ||
293 this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
294 "bug in forced alignment of thread objects");
295 }
296 #endif /* ASSERT */
297 }
298
299 void Thread::initialize_thread_local_storage() {
300 // Note: Make sure this method only calls
301 // non-blocking operations. Otherwise, it might not work
302 // with the thread-startup/safepoint interaction.
303
304 // During Java thread startup, safepoint code should allow this
305 // method to complete because it may need to allocate memory to
306 // store information for the new thread.
307
308 // initialize structure dependent on thread local storage
309 ThreadLocalStorage::set_thread(this);
310 }
311
312 void Thread::record_stack_base_and_size() {
313 set_stack_base(os::current_stack_base());
314 set_stack_size(os::current_stack_size());
315 // CR 7190089: on Solaris, primordial thread's stack is adjusted
316 // in initialize_thread(). Without the adjustment, stack size is
317 // incorrect if stack is set to unlimited (ulimit -s unlimited).
318 // So far, only Solaris has real implementation of initialize_thread().
319 //
320 // set up any platform-specific state.
321 os::initialize_thread(this);
322
323 #if INCLUDE_NMT
324 // record thread's native stack, stack grows downward
325 address stack_low_addr = stack_base() - stack_size();
326 MemTracker::record_thread_stack(stack_low_addr, stack_size(), this,
327 CURRENT_PC);
328 #endif // INCLUDE_NMT
329 }
330
331
332 Thread::~Thread() {
333 // Reclaim the objectmonitors from the omFreeList of the moribund thread.
334 ObjectSynchronizer::omFlush (this) ;
335
336 // stack_base can be NULL if the thread is never started or exited before
337 // record_stack_base_and_size called. Although, we would like to ensure
338 // that all started threads do call record_stack_base_and_size(), there is
339 // not proper way to enforce that.
340 #if INCLUDE_NMT
341 if (_stack_base != NULL) {
342 address low_stack_addr = stack_base() - stack_size();
343 MemTracker::release_thread_stack(low_stack_addr, stack_size(), this);
344 #ifdef ASSERT
345 set_stack_base(NULL);
346 #endif
347 }
348 #endif // INCLUDE_NMT
349
350 // deallocate data structures
351 delete resource_area();
352 // since the handle marks are using the handle area, we have to deallocated the root
353 // handle mark before deallocating the thread's handle area,
354 assert(last_handle_mark() != NULL, "check we have an element");
355 delete last_handle_mark();
356 assert(last_handle_mark() == NULL, "check we have reached the end");
357
358 // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
359 // We NULL out the fields for good hygiene.
360 ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ;
361 ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ;
362 ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ;
363 ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ;
364
365 delete handle_area();
366 delete metadata_handles();
367
368 // osthread() can be NULL, if creation of thread failed.
369 if (osthread() != NULL) os::free_thread(osthread());
370
371 delete _SR_lock;
372
373 // clear thread local storage if the Thread is deleting itself
374 if (this == Thread::current()) {
375 ThreadLocalStorage::set_thread(NULL);
376 } else {
377 // In the case where we're not the current thread, invalidate all the
378 // caches in case some code tries to get the current thread or the
379 // thread that was destroyed, and gets stale information.
380 ThreadLocalStorage::invalidate_all();
381 }
382 CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
383 }
384
385 // NOTE: dummy function for assertion purpose.
386 void Thread::run() {
387 ShouldNotReachHere();
388 }
389
390 #ifdef ASSERT
391 // Private method to check for dangling thread pointer
392 void check_for_dangling_thread_pointer(Thread *thread) {
393 assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
394 "possibility of dangling Thread pointer");
395 }
396 #endif
397
398
399 #ifndef PRODUCT
400 // Tracing method for basic thread operations
401 void Thread::trace(const char* msg, const Thread* const thread) {
402 if (!TraceThreadEvents) return;
403 ResourceMark rm;
404 ThreadCritical tc;
405 const char *name = "non-Java thread";
406 int prio = -1;
407 if (thread->is_Java_thread()
408 && !thread->is_Compiler_thread()) {
409 // The Threads_lock must be held to get information about
410 // this thread but may not be in some situations when
411 // tracing thread events.
412 bool release_Threads_lock = false;
413 if (!Threads_lock->owned_by_self()) {
414 Threads_lock->lock();
415 release_Threads_lock = true;
416 }
417 JavaThread* jt = (JavaThread *)thread;
418 name = (char *)jt->get_thread_name();
419 oop thread_oop = jt->threadObj();
420 if (thread_oop != NULL) {
421 prio = java_lang_Thread::priority(thread_oop);
422 }
423 if (release_Threads_lock) {
424 Threads_lock->unlock();
425 }
426 }
427 tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
428 }
429 #endif
430
431
432 ThreadPriority Thread::get_priority(const Thread* const thread) {
433 trace("get priority", thread);
434 ThreadPriority priority;
435 // Can return an error!
436 (void)os::get_priority(thread, priority);
437 assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
438 return priority;
439 }
440
441 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
442 trace("set priority", thread);
443 debug_only(check_for_dangling_thread_pointer(thread);)
444 // Can return an error!
445 (void)os::set_priority(thread, priority);
446 }
447
448
449 void Thread::start(Thread* thread) {
450 trace("start", thread);
451 // Start is different from resume in that its safety is guaranteed by context or
452 // being called from a Java method synchronized on the Thread object.
453 if (!DisableStartThread) {
454 if (thread->is_Java_thread()) {
455 // Initialize the thread state to RUNNABLE before starting this thread.
456 // Can not set it after the thread started because we do not know the
457 // exact thread state at that time. It could be in MONITOR_WAIT or
458 // in SLEEPING or some other state.
459 java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
460 java_lang_Thread::RUNNABLE);
461 }
462 os::start_thread(thread);
463 }
464 }
465
466 // Enqueue a VM_Operation to do the job for us - sometime later
467 void Thread::send_async_exception(oop java_thread, oop java_throwable) {
468 VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
469 VMThread::execute(vm_stop);
470 }
471
472
473 //
474 // Check if an external suspend request has completed (or has been
475 // cancelled). Returns true if the thread is externally suspended and
476 // false otherwise.
477 //
478 // The bits parameter returns information about the code path through
479 // the routine. Useful for debugging:
480 //
481 // set in is_ext_suspend_completed():
482 // 0x00000001 - routine was entered
483 // 0x00000010 - routine return false at end
484 // 0x00000100 - thread exited (return false)
485 // 0x00000200 - suspend request cancelled (return false)
486 // 0x00000400 - thread suspended (return true)
487 // 0x00001000 - thread is in a suspend equivalent state (return true)
488 // 0x00002000 - thread is native and walkable (return true)
489 // 0x00004000 - thread is native_trans and walkable (needed retry)
490 //
491 // set in wait_for_ext_suspend_completion():
492 // 0x00010000 - routine was entered
493 // 0x00020000 - suspend request cancelled before loop (return false)
494 // 0x00040000 - thread suspended before loop (return true)
495 // 0x00080000 - suspend request cancelled in loop (return false)
496 // 0x00100000 - thread suspended in loop (return true)
497 // 0x00200000 - suspend not completed during retry loop (return false)
498 //
499
500 // Helper class for tracing suspend wait debug bits.
501 //
502 // 0x00000100 indicates that the target thread exited before it could
503 // self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
504 // 0x00080000 each indicate a cancelled suspend request so they don't
505 // count as wait failures either.
506 #define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
507
508 class TraceSuspendDebugBits : public StackObj {
509 private:
510 JavaThread * jt;
511 bool is_wait;
512 bool called_by_wait; // meaningful when !is_wait
513 uint32_t * bits;
514
515 public:
516 TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
517 uint32_t *_bits) {
518 jt = _jt;
519 is_wait = _is_wait;
520 called_by_wait = _called_by_wait;
521 bits = _bits;
522 }
523
524 ~TraceSuspendDebugBits() {
525 if (!is_wait) {
526 #if 1
527 // By default, don't trace bits for is_ext_suspend_completed() calls.
528 // That trace is very chatty.
529 return;
530 #else
531 if (!called_by_wait) {
532 // If tracing for is_ext_suspend_completed() is enabled, then only
533 // trace calls to it from wait_for_ext_suspend_completion()
534 return;
535 }
536 #endif
537 }
538
539 if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
540 if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
541 MutexLocker ml(Threads_lock); // needed for get_thread_name()
542 ResourceMark rm;
543
544 tty->print_cr(
545 "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
546 jt->get_thread_name(), *bits);
547
548 guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
549 }
550 }
551 }
552 };
553 #undef DEBUG_FALSE_BITS
554
555
556 bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) {
557 TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
558
559 bool did_trans_retry = false; // only do thread_in_native_trans retry once
560 bool do_trans_retry; // flag to force the retry
561
562 *bits |= 0x00000001;
563
564 do {
565 do_trans_retry = false;
566
567 if (is_exiting()) {
568 // Thread is in the process of exiting. This is always checked
569 // first to reduce the risk of dereferencing a freed JavaThread.
570 *bits |= 0x00000100;
571 return false;
572 }
573
574 if (!is_external_suspend()) {
575 // Suspend request is cancelled. This is always checked before
576 // is_ext_suspended() to reduce the risk of a rogue resume
577 // confusing the thread that made the suspend request.
578 *bits |= 0x00000200;
579 return false;
580 }
581
582 if (is_ext_suspended()) {
583 // thread is suspended
584 *bits |= 0x00000400;
585 return true;
586 }
587
588 // Now that we no longer do hard suspends of threads running
589 // native code, the target thread can be changing thread state
590 // while we are in this routine:
591 //
592 // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
593 //
594 // We save a copy of the thread state as observed at this moment
595 // and make our decision about suspend completeness based on the
596 // copy. This closes the race where the thread state is seen as
597 // _thread_in_native_trans in the if-thread_blocked check, but is
598 // seen as _thread_blocked in if-thread_in_native_trans check.
599 JavaThreadState save_state = thread_state();
600
601 if (save_state == _thread_blocked && is_suspend_equivalent()) {
602 // If the thread's state is _thread_blocked and this blocking
603 // condition is known to be equivalent to a suspend, then we can
604 // consider the thread to be externally suspended. This means that
605 // the code that sets _thread_blocked has been modified to do
606 // self-suspension if the blocking condition releases. We also
607 // used to check for CONDVAR_WAIT here, but that is now covered by
608 // the _thread_blocked with self-suspension check.
609 //
610 // Return true since we wouldn't be here unless there was still an
611 // external suspend request.
612 *bits |= 0x00001000;
613 return true;
614 } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
615 // Threads running native code will self-suspend on native==>VM/Java
616 // transitions. If its stack is walkable (should always be the case
617 // unless this function is called before the actual java_suspend()
618 // call), then the wait is done.
619 *bits |= 0x00002000;
620 return true;
621 } else if (!called_by_wait && !did_trans_retry &&
622 save_state == _thread_in_native_trans &&
623 frame_anchor()->walkable()) {
624 // The thread is transitioning from thread_in_native to another
625 // thread state. check_safepoint_and_suspend_for_native_trans()
626 // will force the thread to self-suspend. If it hasn't gotten
627 // there yet we may have caught the thread in-between the native
628 // code check above and the self-suspend. Lucky us. If we were
629 // called by wait_for_ext_suspend_completion(), then it
630 // will be doing the retries so we don't have to.
631 //
632 // Since we use the saved thread state in the if-statement above,
633 // there is a chance that the thread has already transitioned to
634 // _thread_blocked by the time we get here. In that case, we will
635 // make a single unnecessary pass through the logic below. This
636 // doesn't hurt anything since we still do the trans retry.
637
638 *bits |= 0x00004000;
639
640 // Once the thread leaves thread_in_native_trans for another
641 // thread state, we break out of this retry loop. We shouldn't
642 // need this flag to prevent us from getting back here, but
643 // sometimes paranoia is good.
644 did_trans_retry = true;
645
646 // We wait for the thread to transition to a more usable state.
647 for (int i = 1; i <= SuspendRetryCount; i++) {
648 // We used to do an "os::yield_all(i)" call here with the intention
649 // that yielding would increase on each retry. However, the parameter
650 // is ignored on Linux which means the yield didn't scale up. Waiting
651 // on the SR_lock below provides a much more predictable scale up for
652 // the delay. It also provides a simple/direct point to check for any
653 // safepoint requests from the VMThread
654
655 // temporarily drops SR_lock while doing wait with safepoint check
656 // (if we're a JavaThread - the WatcherThread can also call this)
657 // and increase delay with each retry
658 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
659
660 // check the actual thread state instead of what we saved above
661 if (thread_state() != _thread_in_native_trans) {
662 // the thread has transitioned to another thread state so
663 // try all the checks (except this one) one more time.
664 do_trans_retry = true;
665 break;
666 }
667 } // end retry loop
668
669
670 }
671 } while (do_trans_retry);
672
673 *bits |= 0x00000010;
674 return false;
675 }
676
677 //
678 // Wait for an external suspend request to complete (or be cancelled).
679 // Returns true if the thread is externally suspended and false otherwise.
680 //
681 bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
682 uint32_t *bits) {
683 TraceSuspendDebugBits tsdb(this, true /* is_wait */,
684 false /* !called_by_wait */, bits);
685
686 // local flag copies to minimize SR_lock hold time
687 bool is_suspended;
688 bool pending;
689 uint32_t reset_bits;
690
691 // set a marker so is_ext_suspend_completed() knows we are the caller
692 *bits |= 0x00010000;
693
694 // We use reset_bits to reinitialize the bits value at the top of
695 // each retry loop. This allows the caller to make use of any
696 // unused bits for their own marking purposes.
697 reset_bits = *bits;
698
699 {
700 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
701 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
702 delay, bits);
703 pending = is_external_suspend();
704 }
705 // must release SR_lock to allow suspension to complete
706
707 if (!pending) {
708 // A cancelled suspend request is the only false return from
709 // is_ext_suspend_completed() that keeps us from entering the
710 // retry loop.
711 *bits |= 0x00020000;
712 return false;
713 }
714
715 if (is_suspended) {
716 *bits |= 0x00040000;
717 return true;
718 }
719
720 for (int i = 1; i <= retries; i++) {
721 *bits = reset_bits; // reinit to only track last retry
722
723 // We used to do an "os::yield_all(i)" call here with the intention
724 // that yielding would increase on each retry. However, the parameter
725 // is ignored on Linux which means the yield didn't scale up. Waiting
726 // on the SR_lock below provides a much more predictable scale up for
727 // the delay. It also provides a simple/direct point to check for any
728 // safepoint requests from the VMThread
729
730 {
731 MutexLocker ml(SR_lock());
732 // wait with safepoint check (if we're a JavaThread - the WatcherThread
733 // can also call this) and increase delay with each retry
734 SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
735
736 is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
737 delay, bits);
738
739 // It is possible for the external suspend request to be cancelled
740 // (by a resume) before the actual suspend operation is completed.
741 // Refresh our local copy to see if we still need to wait.
742 pending = is_external_suspend();
743 }
744
745 if (!pending) {
746 // A cancelled suspend request is the only false return from
747 // is_ext_suspend_completed() that keeps us from staying in the
748 // retry loop.
749 *bits |= 0x00080000;
750 return false;
751 }
752
753 if (is_suspended) {
754 *bits |= 0x00100000;
755 return true;
756 }
757 } // end retry loop
758
759 // thread did not suspend after all our retries
760 *bits |= 0x00200000;
761 return false;
762 }
763
764 #ifndef PRODUCT
765 void JavaThread::record_jump(address target, address instr, const char* file, int line) {
766
767 // This should not need to be atomic as the only way for simultaneous
768 // updates is via interrupts. Even then this should be rare or non-existant
769 // and we don't care that much anyway.
770
771 int index = _jmp_ring_index;
772 _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1);
773 _jmp_ring[index]._target = (intptr_t) target;
774 _jmp_ring[index]._instruction = (intptr_t) instr;
775 _jmp_ring[index]._file = file;
776 _jmp_ring[index]._line = line;
777 }
778 #endif /* PRODUCT */
779
780 // Called by flat profiler
781 // Callers have already called wait_for_ext_suspend_completion
782 // The assertion for that is currently too complex to put here:
783 bool JavaThread::profile_last_Java_frame(frame* _fr) {
784 bool gotframe = false;
785 // self suspension saves needed state.
786 if (has_last_Java_frame() && _anchor.walkable()) {
787 *_fr = pd_last_frame();
788 gotframe = true;
789 }
790 return gotframe;
791 }
792
793 void Thread::interrupt(Thread* thread) {
794 trace("interrupt", thread);
795 debug_only(check_for_dangling_thread_pointer(thread);)
796 os::interrupt(thread);
797 }
798
799 bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
800 trace("is_interrupted", thread);
801 debug_only(check_for_dangling_thread_pointer(thread);)
802 // Note: If clear_interrupted==false, this simply fetches and
803 // returns the value of the field osthread()->interrupted().
804 return os::is_interrupted(thread, clear_interrupted);
805 }
806
807
808 // GC Support
809 bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
810 jint thread_parity = _oops_do_parity;
811 if (thread_parity != strong_roots_parity) {
812 jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
813 if (res == thread_parity) {
814 return true;
815 } else {
816 guarantee(res == strong_roots_parity, "Or else what?");
817 assert(SharedHeap::heap()->workers()->active_workers() > 0,
818 "Should only fail when parallel.");
819 return false;
820 }
821 }
822 assert(SharedHeap::heap()->workers()->active_workers() > 0,
823 "Should only fail when parallel.");
824 return false;
825 }
826
827 void Thread::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) {
828 active_handles()->oops_do(f);
829 // Do oop for ThreadShadow
830 f->do_oop((oop*)&_pending_exception);
831 handle_area()->oops_do(f);
832 }
833
834 void Thread::nmethods_do(CodeBlobClosure* cf) {
835 // no nmethods in a generic thread...
836 }
837
838 void Thread::metadata_do(void f(Metadata*)) {
839 if (metadata_handles() != NULL) {
840 for (int i = 0; i< metadata_handles()->length(); i++) {
841 f(metadata_handles()->at(i));
842 }
843 }
844 }
845
846 void Thread::print_on(outputStream* st) const {
847 // get_priority assumes osthread initialized
848 if (osthread() != NULL) {
849 int os_prio;
850 if (os::get_native_priority(this, &os_prio) == OS_OK) {
851 st->print("os_prio=%d ", os_prio);
852 }
853 st->print("tid=" INTPTR_FORMAT " ", this);
854 osthread()->print_on(st);
855 }
856 debug_only(if (WizardMode) print_owned_locks_on(st);)
857 }
858
859 // Thread::print_on_error() is called by fatal error handler. Don't use
860 // any lock or allocate memory.
861 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
862 if (is_VM_thread()) st->print("VMThread");
863 else if (is_Compiler_thread()) st->print("CompilerThread");
864 else if (is_Java_thread()) st->print("JavaThread");
865 else if (is_GC_task_thread()) st->print("GCTaskThread");
866 else if (is_Watcher_thread()) st->print("WatcherThread");
867 else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread");
868 else st->print("Thread");
869
870 st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
871 _stack_base - _stack_size, _stack_base);
872
873 if (osthread()) {
874 st->print(" [id=%d]", osthread()->thread_id());
875 }
876 }
877
878 #ifdef ASSERT
879 void Thread::print_owned_locks_on(outputStream* st) const {
880 Monitor *cur = _owned_locks;
881 if (cur == NULL) {
882 st->print(" (no locks) ");
883 } else {
884 st->print_cr(" Locks owned:");
885 while(cur) {
886 cur->print_on(st);
887 cur = cur->next();
888 }
889 }
890 }
891
892 static int ref_use_count = 0;
893
894 bool Thread::owns_locks_but_compiled_lock() const {
895 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
896 if (cur != Compile_lock) return true;
897 }
898 return false;
899 }
900
901
902 #endif
903
904 #ifndef PRODUCT
905
906 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
907 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
908 // no threads which allow_vm_block's are held
909 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
910 // Check if current thread is allowed to block at a safepoint
911 if (!(_allow_safepoint_count == 0))
912 fatal("Possible safepoint reached by thread that does not allow it");
913 if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
914 fatal("LEAF method calling lock?");
915 }
916
917 #ifdef ASSERT
918 if (potential_vm_operation && is_Java_thread()
919 && !Universe::is_bootstrapping()) {
920 // Make sure we do not hold any locks that the VM thread also uses.
921 // This could potentially lead to deadlocks
922 for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
923 // Threads_lock is special, since the safepoint synchronization will not start before this is
924 // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
925 // since it is used to transfer control between JavaThreads and the VMThread
926 // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
927 if ( (cur->allow_vm_block() &&
928 cur != Threads_lock &&
929 cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation
930 cur != VMOperationRequest_lock &&
931 cur != VMOperationQueue_lock) ||
932 cur->rank() == Mutex::special) {
933 warning("Thread holding lock at safepoint that vm can block on: %s", cur->name());
934 }
935 }
936 }
937
938 if (GCALotAtAllSafepoints) {
939 // We could enter a safepoint here and thus have a gc
940 InterfaceSupport::check_gc_alot();
941 }
942 #endif
943 }
944 #endif
945
946 bool Thread::is_in_stack(address adr) const {
947 assert(Thread::current() == this, "is_in_stack can only be called from current thread");
948 address end = os::current_stack_pointer();
949 // Allow non Java threads to call this without stack_base
950 if (_stack_base == NULL) return true;
951 if (stack_base() >= adr && adr >= end) return true;
952
953 return false;
954 }
955
956
957 // We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
958 // However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
959 // used for compilation in the future. If that change is made, the need for these methods
960 // should be revisited, and they should be removed if possible.
961
962 bool Thread::is_lock_owned(address adr) const {
963 return on_local_stack(adr);
964 }
965
966 bool Thread::set_as_starting_thread() {
967 // NOTE: this must be called inside the main thread.
968 return os::create_main_thread((JavaThread*)this);
969 }
970
971 static void initialize_class(Symbol* class_name, TRAPS) {
972 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
973 InstanceKlass::cast(klass)->initialize(CHECK);
974 }
975
976
977 // Creates the initial ThreadGroup
978 static Handle create_initial_thread_group(TRAPS) {
979 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH);
980 instanceKlassHandle klass (THREAD, k);
981
982 Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
983 {
984 JavaValue result(T_VOID);
985 JavaCalls::call_special(&result,
986 system_instance,
987 klass,
988 vmSymbols::object_initializer_name(),
989 vmSymbols::void_method_signature(),
990 CHECK_NH);
991 }
992 Universe::set_system_thread_group(system_instance());
993
994 Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
995 {
996 JavaValue result(T_VOID);
997 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
998 JavaCalls::call_special(&result,
999 main_instance,
1000 klass,
1001 vmSymbols::object_initializer_name(),
1002 vmSymbols::threadgroup_string_void_signature(),
1003 system_instance,
1004 string,
1005 CHECK_NH);
1006 }
1007 return main_instance;
1008 }
1009
1010 // Creates the initial Thread
1011 static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
1012 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL);
1013 instanceKlassHandle klass (THREAD, k);
1014 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
1015
1016 java_lang_Thread::set_thread(thread_oop(), thread);
1017 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1018 thread->set_threadObj(thread_oop());
1019
1020 Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
1021
1022 JavaValue result(T_VOID);
1023 JavaCalls::call_special(&result, thread_oop,
1024 klass,
1025 vmSymbols::object_initializer_name(),
1026 vmSymbols::threadgroup_string_void_signature(),
1027 thread_group,
1028 string,
1029 CHECK_NULL);
1030 return thread_oop();
1031 }
1032
1033 static void call_initializeSystemClass(TRAPS) {
1034 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1035 instanceKlassHandle klass (THREAD, k);
1036
1037 JavaValue result(T_VOID);
1038 JavaCalls::call_static(&result, klass, vmSymbols::initializeSystemClass_name(),
1039 vmSymbols::void_method_signature(), CHECK);
1040 }
1041
1042 char java_runtime_name[128] = "";
1043 char java_runtime_version[128] = "";
1044
1045 // extract the JRE name from sun.misc.Version.java_runtime_name
1046 static const char* get_java_runtime_name(TRAPS) {
1047 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(),
1048 Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1049 fieldDescriptor fd;
1050 bool found = k != NULL &&
1051 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_name_name(),
1052 vmSymbols::string_signature(), &fd);
1053 if (found) {
1054 oop name_oop = k->java_mirror()->obj_field(fd.offset());
1055 if (name_oop == NULL)
1056 return NULL;
1057 const char* name = java_lang_String::as_utf8_string(name_oop,
1058 java_runtime_name,
1059 sizeof(java_runtime_name));
1060 return name;
1061 } else {
1062 return NULL;
1063 }
1064 }
1065
1066 // extract the JRE version from sun.misc.Version.java_runtime_version
1067 static const char* get_java_runtime_version(TRAPS) {
1068 Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(),
1069 Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1070 fieldDescriptor fd;
1071 bool found = k != NULL &&
1072 InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_version_name(),
1073 vmSymbols::string_signature(), &fd);
1074 if (found) {
1075 oop name_oop = k->java_mirror()->obj_field(fd.offset());
1076 if (name_oop == NULL)
1077 return NULL;
1078 const char* name = java_lang_String::as_utf8_string(name_oop,
1079 java_runtime_version,
1080 sizeof(java_runtime_version));
1081 return name;
1082 } else {
1083 return NULL;
1084 }
1085 }
1086
1087 // General purpose hook into Java code, run once when the VM is initialized.
1088 // The Java library method itself may be changed independently from the VM.
1089 static void call_postVMInitHook(TRAPS) {
1090 Klass* k = SystemDictionary::PostVMInitHook_klass();
1091 instanceKlassHandle klass (THREAD, k);
1092 if (klass.not_null()) {
1093 JavaValue result(T_VOID);
1094 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
1095 vmSymbols::void_method_signature(),
1096 CHECK);
1097 }
1098 }
1099
1100 static void reset_vm_info_property(TRAPS) {
1101 // the vm info string
1102 ResourceMark rm(THREAD);
1103 const char *vm_info = VM_Version::vm_info_string();
1104
1105 // java.lang.System class
1106 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1107 instanceKlassHandle klass (THREAD, k);
1108
1109 // setProperty arguments
1110 Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
1111 Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
1112
1113 // return value
1114 JavaValue r(T_OBJECT);
1115
1116 // public static String setProperty(String key, String value);
1117 JavaCalls::call_static(&r,
1118 klass,
1119 vmSymbols::setProperty_name(),
1120 vmSymbols::string_string_string_signature(),
1121 key_str,
1122 value_str,
1123 CHECK);
1124 }
1125
1126
1127 void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
1128 assert(thread_group.not_null(), "thread group should be specified");
1129 assert(threadObj() == NULL, "should only create Java thread object once");
1130
1131 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
1132 instanceKlassHandle klass (THREAD, k);
1133 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
1134
1135 java_lang_Thread::set_thread(thread_oop(), this);
1136 java_lang_Thread::set_priority(thread_oop(), NormPriority);
1137 set_threadObj(thread_oop());
1138
1139 JavaValue result(T_VOID);
1140 if (thread_name != NULL) {
1141 Handle name = java_lang_String::create_from_str(thread_name, CHECK);
1142 // Thread gets assigned specified name and null target
1143 JavaCalls::call_special(&result,
1144 thread_oop,
1145 klass,
1146 vmSymbols::object_initializer_name(),
1147 vmSymbols::threadgroup_string_void_signature(),
1148 thread_group, // Argument 1
1149 name, // Argument 2
1150 THREAD);
1151 } else {
1152 // Thread gets assigned name "Thread-nnn" and null target
1153 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
1154 JavaCalls::call_special(&result,
1155 thread_oop,
1156 klass,
1157 vmSymbols::object_initializer_name(),
1158 vmSymbols::threadgroup_runnable_void_signature(),
1159 thread_group, // Argument 1
1160 Handle(), // Argument 2
1161 THREAD);
1162 }
1163
1164
1165 if (daemon) {
1166 java_lang_Thread::set_daemon(thread_oop());
1167 }
1168
1169 if (HAS_PENDING_EXCEPTION) {
1170 return;
1171 }
1172
1173 KlassHandle group(this, SystemDictionary::ThreadGroup_klass());
1174 Handle threadObj(this, this->threadObj());
1175
1176 JavaCalls::call_special(&result,
1177 thread_group,
1178 group,
1179 vmSymbols::add_method_name(),
1180 vmSymbols::thread_void_signature(),
1181 threadObj, // Arg 1
1182 THREAD);
1183
1184
1185 }
1186
1187 // NamedThread -- non-JavaThread subclasses with multiple
1188 // uniquely named instances should derive from this.
1189 NamedThread::NamedThread() : Thread() {
1190 _name = NULL;
1191 _processed_thread = NULL;
1192 }
1193
1194 NamedThread::~NamedThread() {
1195 if (_name != NULL) {
1196 FREE_C_HEAP_ARRAY(char, _name, mtThread);
1197 _name = NULL;
1198 }
1199 }
1200
1201 void NamedThread::set_name(const char* format, ...) {
1202 guarantee(_name == NULL, "Only get to set name once.");
1203 _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread);
1204 guarantee(_name != NULL, "alloc failure");
1205 va_list ap;
1206 va_start(ap, format);
1207 jio_vsnprintf(_name, max_name_len, format, ap);
1208 va_end(ap);
1209 }
1210
1211 // ======= WatcherThread ========
1212
1213 // The watcher thread exists to simulate timer interrupts. It should
1214 // be replaced by an abstraction over whatever native support for
1215 // timer interrupts exists on the platform.
1216
1217 WatcherThread* WatcherThread::_watcher_thread = NULL;
1218 bool WatcherThread::_startable = false;
1219 volatile bool WatcherThread::_should_terminate = false;
1220
1221 WatcherThread::WatcherThread() : Thread() {
1222 assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1223 if (os::create_thread(this, os::watcher_thread)) {
1224 _watcher_thread = this;
1225
1226 // Set the watcher thread to the highest OS priority which should not be
1227 // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1228 // is created. The only normal thread using this priority is the reference
1229 // handler thread, which runs for very short intervals only.
1230 // If the VMThread's priority is not lower than the WatcherThread profiling
1231 // will be inaccurate.
1232 os::set_priority(this, MaxPriority);
1233 if (!DisableStartThread) {
1234 os::start_thread(this);
1235 }
1236 }
1237 }
1238
1239 int WatcherThread::sleep() const {
1240 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1241
1242 // remaining will be zero if there are no tasks,
1243 // causing the WatcherThread to sleep until a task is
1244 // enrolled
1245 int remaining = PeriodicTask::time_to_wait();
1246 int time_slept = 0;
1247
1248 // we expect this to timeout - we only ever get unparked when
1249 // we should terminate or when a new task has been enrolled
1250 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
1251
1252 jlong time_before_loop = os::javaTimeNanos();
1253
1254 for (;;) {
1255 bool timedout = PeriodicTask_lock->wait(Mutex::_no_safepoint_check_flag, remaining);
1256 jlong now = os::javaTimeNanos();
1257
1258 if (remaining == 0) {
1259 // if we didn't have any tasks we could have waited for a long time
1260 // consider the time_slept zero and reset time_before_loop
1261 time_slept = 0;
1262 time_before_loop = now;
1263 } else {
1264 // need to recalulate since we might have new tasks in _tasks
1265 time_slept = (int) ((now - time_before_loop) / 1000000);
1266 }
1267
1268 // Change to task list or spurious wakeup of some kind
1269 if (timedout || _should_terminate) {
1270 break;
1271 }
1272
1273 remaining = PeriodicTask::time_to_wait();
1274 if (remaining == 0) {
1275 // Last task was just disenrolled so loop around and wait until
1276 // another task gets enrolled
1277 continue;
1278 }
1279
1280 remaining -= time_slept;
1281 if (remaining <= 0)
1282 break;
1283 }
1284
1285 return time_slept;
1286 }
1287
1288 void WatcherThread::run() {
1289 assert(this == watcher_thread(), "just checking");
1290
1291 this->record_stack_base_and_size();
1292 this->initialize_thread_local_storage();
1293 this->set_active_handles(JNIHandleBlock::allocate_block());
1294 while(!_should_terminate) {
1295 assert(watcher_thread() == Thread::current(), "thread consistency check");
1296 assert(watcher_thread() == this, "thread consistency check");
1297
1298 // Calculate how long it'll be until the next PeriodicTask work
1299 // should be done, and sleep that amount of time.
1300 int time_waited = sleep();
1301
1302 if (is_error_reported()) {
1303 // A fatal error has happened, the error handler(VMError::report_and_die)
1304 // should abort JVM after creating an error log file. However in some
1305 // rare cases, the error handler itself might deadlock. Here we try to
1306 // kill JVM if the fatal error handler fails to abort in 2 minutes.
1307 //
1308 // This code is in WatcherThread because WatcherThread wakes up
1309 // periodically so the fatal error handler doesn't need to do anything;
1310 // also because the WatcherThread is less likely to crash than other
1311 // threads.
1312
1313 for (;;) {
1314 if (!ShowMessageBoxOnError
1315 && (OnError == NULL || OnError[0] == '\0')
1316 && Arguments::abort_hook() == NULL) {
1317 os::sleep(this, 2 * 60 * 1000, false);
1318 fdStream err(defaultStream::output_fd());
1319 err.print_raw_cr("# [ timer expired, abort... ]");
1320 // skip atexit/vm_exit/vm_abort hooks
1321 os::die();
1322 }
1323
1324 // Wake up 5 seconds later, the fatal handler may reset OnError or
1325 // ShowMessageBoxOnError when it is ready to abort.
1326 os::sleep(this, 5 * 1000, false);
1327 }
1328 }
1329
1330 PeriodicTask::real_time_tick(time_waited);
1331 }
1332
1333 // Signal that it is terminated
1334 {
1335 MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1336 _watcher_thread = NULL;
1337 Terminator_lock->notify();
1338 }
1339
1340 // Thread destructor usually does this..
1341 ThreadLocalStorage::set_thread(NULL);
1342 }
1343
1344 void WatcherThread::start() {
1345 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1346
1347 if (watcher_thread() == NULL && _startable) {
1348 _should_terminate = false;
1349 // Create the single instance of WatcherThread
1350 new WatcherThread();
1351 }
1352 }
1353
1354 void WatcherThread::make_startable() {
1355 assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1356 _startable = true;
1357 }
1358
1359 void WatcherThread::stop() {
1360 {
1361 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1362 _should_terminate = true;
1363 OrderAccess::fence(); // ensure WatcherThread sees update in main loop
1364
1365 WatcherThread* watcher = watcher_thread();
1366 if (watcher != NULL)
1367 watcher->unpark();
1368 }
1369
1370 // it is ok to take late safepoints here, if needed
1371 MutexLocker mu(Terminator_lock);
1372
1373 while(watcher_thread() != NULL) {
1374 // This wait should make safepoint checks, wait without a timeout,
1375 // and wait as a suspend-equivalent condition.
1376 //
1377 // Note: If the FlatProfiler is running, then this thread is waiting
1378 // for the WatcherThread to terminate and the WatcherThread, via the
1379 // FlatProfiler task, is waiting for the external suspend request on
1380 // this thread to complete. wait_for_ext_suspend_completion() will
1381 // eventually timeout, but that takes time. Making this wait a
1382 // suspend-equivalent condition solves that timeout problem.
1383 //
1384 Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1385 Mutex::_as_suspend_equivalent_flag);
1386 }
1387 }
1388
1389 void WatcherThread::unpark() {
1390 MutexLockerEx ml(PeriodicTask_lock->owned_by_self() ? NULL : PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1391 PeriodicTask_lock->notify();
1392 }
1393
1394 void WatcherThread::print_on(outputStream* st) const {
1395 st->print("\"%s\" ", name());
1396 Thread::print_on(st);
1397 st->cr();
1398 }
1399
1400 // ======= JavaThread ========
1401
1402 // A JavaThread is a normal Java thread
1403
1404 void JavaThread::initialize() {
1405 // Initialize fields
1406
1407 // Set the claimed par_id to -1 (ie not claiming any par_ids)
1408 set_claimed_par_id(-1);
1409
1410 set_saved_exception_pc(NULL);
1411 set_threadObj(NULL);
1412 _anchor.clear();
1413 set_entry_point(NULL);
1414 set_jni_functions(jni_functions());
1415 set_callee_target(NULL);
1416 set_vm_result(NULL);
1417 set_vm_result_2(NULL);
1418 set_vframe_array_head(NULL);
1419 set_vframe_array_last(NULL);
1420 set_deferred_locals(NULL);
1421 set_deopt_mark(NULL);
1422 set_deopt_nmethod(NULL);
1423 clear_must_deopt_id();
1424 set_monitor_chunks(NULL);
1425 set_next(NULL);
1426 set_thread_state(_thread_new);
1427 #if INCLUDE_NMT
1428 set_recorder(NULL);
1429 #endif
1430 _terminated = _not_terminated;
1431 _privileged_stack_top = NULL;
1432 _array_for_gc = NULL;
1433 _suspend_equivalent = false;
1434 _in_deopt_handler = 0;
1435 _doing_unsafe_access = false;
1436 _stack_guard_state = stack_guard_unused;
1437 _exception_oop = NULL;
1438 _exception_pc = 0;
1439 _exception_handler_pc = 0;
1440 _is_method_handle_return = 0;
1441 _jvmti_thread_state= NULL;
1442 _should_post_on_exceptions_flag = JNI_FALSE;
1443 _jvmti_get_loaded_classes_closure = NULL;
1444 _interp_only_mode = 0;
1445 _special_runtime_exit_condition = _no_async_condition;
1446 _pending_async_exception = NULL;
1447 _is_compiling = false;
1448 _thread_stat = NULL;
1449 _thread_stat = new ThreadStatistics();
1450 _blocked_on_compilation = false;
1451 _jni_active_critical = 0;
1452 _do_not_unlock_if_synchronized = false;
1453 _cached_monitor_info = NULL;
1454 _parker = Parker::Allocate(this) ;
1455
1456 #ifndef PRODUCT
1457 _jmp_ring_index = 0;
1458 for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1459 record_jump(NULL, NULL, NULL, 0);
1460 }
1461 #endif /* PRODUCT */
1462
1463 set_thread_profiler(NULL);
1464 if (FlatProfiler::is_active()) {
1465 // This is where we would decide to either give each thread it's own profiler
1466 // or use one global one from FlatProfiler,
1467 // or up to some count of the number of profiled threads, etc.
1468 ThreadProfiler* pp = new ThreadProfiler();
1469 pp->engage();
1470 set_thread_profiler(pp);
1471 }
1472
1473 // Setup safepoint state info for this thread
1474 ThreadSafepointState::create(this);
1475
1476 debug_only(_java_call_counter = 0);
1477
1478 // JVMTI PopFrame support
1479 _popframe_condition = popframe_inactive;
1480 _popframe_preserved_args = NULL;
1481 _popframe_preserved_args_size = 0;
1482
1483 pd_initialize();
1484 }
1485
1486 #if INCLUDE_ALL_GCS
1487 SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1488 DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1489 #endif // INCLUDE_ALL_GCS
1490
1491 JavaThread::JavaThread(bool is_attaching_via_jni) :
1492 Thread()
1493 #if INCLUDE_ALL_GCS
1494 , _satb_mark_queue(&_satb_mark_queue_set),
1495 _dirty_card_queue(&_dirty_card_queue_set)
1496 #endif // INCLUDE_ALL_GCS
1497 {
1498 initialize();
1499 if (is_attaching_via_jni) {
1500 _jni_attach_state = _attaching_via_jni;
1501 } else {
1502 _jni_attach_state = _not_attaching_via_jni;
1503 }
1504 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
1505 _safepoint_visible = false;
1506 }
1507
1508 bool JavaThread::reguard_stack(address cur_sp) {
1509 if (_stack_guard_state != stack_guard_yellow_disabled) {
1510 return true; // Stack already guarded or guard pages not needed.
1511 }
1512
1513 if (register_stack_overflow()) {
1514 // For those architectures which have separate register and
1515 // memory stacks, we must check the register stack to see if
1516 // it has overflowed.
1517 return false;
1518 }
1519
1520 // Java code never executes within the yellow zone: the latter is only
1521 // there to provoke an exception during stack banging. If java code
1522 // is executing there, either StackShadowPages should be larger, or
1523 // some exception code in c1, c2 or the interpreter isn't unwinding
1524 // when it should.
1525 guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1526
1527 enable_stack_yellow_zone();
1528 return true;
1529 }
1530
1531 bool JavaThread::reguard_stack(void) {
1532 return reguard_stack(os::current_stack_pointer());
1533 }
1534
1535
1536 void JavaThread::block_if_vm_exited() {
1537 if (_terminated == _vm_exited) {
1538 // _vm_exited is set at safepoint, and Threads_lock is never released
1539 // we will block here forever
1540 Threads_lock->lock_without_safepoint_check();
1541 ShouldNotReachHere();
1542 }
1543 }
1544
1545
1546 // Remove this ifdef when C1 is ported to the compiler interface.
1547 static void compiler_thread_entry(JavaThread* thread, TRAPS);
1548
1549 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1550 Thread()
1551 #if INCLUDE_ALL_GCS
1552 , _satb_mark_queue(&_satb_mark_queue_set),
1553 _dirty_card_queue(&_dirty_card_queue_set)
1554 #endif // INCLUDE_ALL_GCS
1555 {
1556 if (TraceThreadEvents) {
1557 tty->print_cr("creating thread %p", this);
1558 }
1559 initialize();
1560 _jni_attach_state = _not_attaching_via_jni;
1561 set_entry_point(entry_point);
1562 // Create the native thread itself.
1563 // %note runtime_23
1564 os::ThreadType thr_type = os::java_thread;
1565 thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1566 os::java_thread;
1567 os::create_thread(this, thr_type, stack_sz);
1568 _safepoint_visible = false;
1569 // The _osthread may be NULL here because we ran out of memory (too many threads active).
1570 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1571 // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1572 // the exception consists of creating the exception object & initializing it, initialization
1573 // will leave the VM via a JavaCall and then all locks must be unlocked).
1574 //
1575 // The thread is still suspended when we reach here. Thread must be explicit started
1576 // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1577 // by calling Threads:add. The reason why this is not done here, is because the thread
1578 // object must be fully initialized (take a look at JVM_Start)
1579 }
1580
1581 JavaThread::~JavaThread() {
1582 if (TraceThreadEvents) {
1583 tty->print_cr("terminate thread %p", this);
1584 }
1585
1586 // By now, this thread should already be invisible to safepoint,
1587 // and its per-thread recorder also collected.
1588 assert(!is_safepoint_visible(), "wrong state");
1589 #if INCLUDE_NMT
1590 assert(get_recorder() == NULL, "Already collected");
1591 #endif // INCLUDE_NMT
1592
1593 // JSR166 -- return the parker to the free list
1594 Parker::Release(_parker);
1595 _parker = NULL ;
1596
1597 // Free any remaining previous UnrollBlock
1598 vframeArray* old_array = vframe_array_last();
1599
1600 if (old_array != NULL) {
1601 Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1602 old_array->set_unroll_block(NULL);
1603 delete old_info;
1604 delete old_array;
1605 }
1606
1607 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1608 if (deferred != NULL) {
1609 // This can only happen if thread is destroyed before deoptimization occurs.
1610 assert(deferred->length() != 0, "empty array!");
1611 do {
1612 jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1613 deferred->remove_at(0);
1614 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1615 delete dlv;
1616 } while (deferred->length() != 0);
1617 delete deferred;
1618 }
1619
1620 // All Java related clean up happens in exit
1621 ThreadSafepointState::destroy(this);
1622 if (_thread_profiler != NULL) delete _thread_profiler;
1623 if (_thread_stat != NULL) delete _thread_stat;
1624 }
1625
1626
1627 // The first routine called by a new Java thread
1628 void JavaThread::run() {
1629 // initialize thread-local alloc buffer related fields
1630 this->initialize_tlab();
1631
1632 // used to test validitity of stack trace backs
1633 this->record_base_of_stack_pointer();
1634
1635 // Record real stack base and size.
1636 this->record_stack_base_and_size();
1637
1638 // Initialize thread local storage; set before calling MutexLocker
1639 this->initialize_thread_local_storage();
1640
1641 this->create_stack_guard_pages();
1642
1643 this->cache_global_variables();
1644
1645 // Thread is now sufficient initialized to be handled by the safepoint code as being
1646 // in the VM. Change thread state from _thread_new to _thread_in_vm
1647 ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1648
1649 assert(JavaThread::current() == this, "sanity check");
1650 assert(!Thread::current()->owns_locks(), "sanity check");
1651
1652 DTRACE_THREAD_PROBE(start, this);
1653
1654 // This operation might block. We call that after all safepoint checks for a new thread has
1655 // been completed.
1656 this->set_active_handles(JNIHandleBlock::allocate_block());
1657
1658 if (JvmtiExport::should_post_thread_life()) {
1659 JvmtiExport::post_thread_start(this);
1660 }
1661
1662 EventThreadStart event;
1663 if (event.should_commit()) {
1664 event.set_javalangthread(java_lang_Thread::thread_id(this->threadObj()));
1665 event.commit();
1666 }
1667
1668 // We call another function to do the rest so we are sure that the stack addresses used
1669 // from there will be lower than the stack base just computed
1670 thread_main_inner();
1671
1672 // Note, thread is no longer valid at this point!
1673 }
1674
1675
1676 void JavaThread::thread_main_inner() {
1677 assert(JavaThread::current() == this, "sanity check");
1678 assert(this->threadObj() != NULL, "just checking");
1679
1680 // Execute thread entry point unless this thread has a pending exception
1681 // or has been stopped before starting.
1682 // Note: Due to JVM_StopThread we can have pending exceptions already!
1683 if (!this->has_pending_exception() &&
1684 !java_lang_Thread::is_stillborn(this->threadObj())) {
1685 {
1686 ResourceMark rm(this);
1687 this->set_native_thread_name(this->get_thread_name());
1688 }
1689 HandleMark hm(this);
1690 this->entry_point()(this, this);
1691 }
1692
1693 DTRACE_THREAD_PROBE(stop, this);
1694
1695 this->exit(false);
1696 delete this;
1697 }
1698
1699
1700 static void ensure_join(JavaThread* thread) {
1701 // We do not need to grap the Threads_lock, since we are operating on ourself.
1702 Handle threadObj(thread, thread->threadObj());
1703 assert(threadObj.not_null(), "java thread object must exist");
1704 ObjectLocker lock(threadObj, thread);
1705 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1706 thread->clear_pending_exception();
1707 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1708 java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1709 // Clear the native thread instance - this makes isAlive return false and allows the join()
1710 // to complete once we've done the notify_all below
1711 java_lang_Thread::set_thread(threadObj(), NULL);
1712 lock.notify_all(thread);
1713 // Ignore pending exception (ThreadDeath), since we are exiting anyway
1714 thread->clear_pending_exception();
1715 }
1716
1717
1718 // For any new cleanup additions, please check to see if they need to be applied to
1719 // cleanup_failed_attach_current_thread as well.
1720 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1721 assert(this == JavaThread::current(), "thread consistency check");
1722
1723 HandleMark hm(this);
1724 Handle uncaught_exception(this, this->pending_exception());
1725 this->clear_pending_exception();
1726 Handle threadObj(this, this->threadObj());
1727 assert(threadObj.not_null(), "Java thread object should be created");
1728
1729 if (get_thread_profiler() != NULL) {
1730 get_thread_profiler()->disengage();
1731 ResourceMark rm;
1732 get_thread_profiler()->print(get_thread_name());
1733 }
1734
1735
1736 // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1737 {
1738 EXCEPTION_MARK;
1739
1740 CLEAR_PENDING_EXCEPTION;
1741 }
1742 // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1743 // has to be fixed by a runtime query method
1744 if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1745 // JSR-166: change call from from ThreadGroup.uncaughtException to
1746 // java.lang.Thread.dispatchUncaughtException
1747 if (uncaught_exception.not_null()) {
1748 Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1749 {
1750 EXCEPTION_MARK;
1751 // Check if the method Thread.dispatchUncaughtException() exists. If so
1752 // call it. Otherwise we have an older library without the JSR-166 changes,
1753 // so call ThreadGroup.uncaughtException()
1754 KlassHandle recvrKlass(THREAD, threadObj->klass());
1755 CallInfo callinfo;
1756 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1757 LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1758 vmSymbols::dispatchUncaughtException_name(),
1759 vmSymbols::throwable_void_signature(),
1760 KlassHandle(), false, false, THREAD);
1761 CLEAR_PENDING_EXCEPTION;
1762 methodHandle method = callinfo.selected_method();
1763 if (method.not_null()) {
1764 JavaValue result(T_VOID);
1765 JavaCalls::call_virtual(&result,
1766 threadObj, thread_klass,
1767 vmSymbols::dispatchUncaughtException_name(),
1768 vmSymbols::throwable_void_signature(),
1769 uncaught_exception,
1770 THREAD);
1771 } else {
1772 KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass());
1773 JavaValue result(T_VOID);
1774 JavaCalls::call_virtual(&result,
1775 group, thread_group,
1776 vmSymbols::uncaughtException_name(),
1777 vmSymbols::thread_throwable_void_signature(),
1778 threadObj, // Arg 1
1779 uncaught_exception, // Arg 2
1780 THREAD);
1781 }
1782 if (HAS_PENDING_EXCEPTION) {
1783 ResourceMark rm(this);
1784 jio_fprintf(defaultStream::error_stream(),
1785 "\nException: %s thrown from the UncaughtExceptionHandler"
1786 " in thread \"%s\"\n",
1787 pending_exception()->klass()->external_name(),
1788 get_thread_name());
1789 CLEAR_PENDING_EXCEPTION;
1790 }
1791 }
1792 }
1793
1794 // Called before the java thread exit since we want to read info
1795 // from java_lang_Thread object
1796 EventThreadEnd event;
1797 if (event.should_commit()) {
1798 event.set_javalangthread(java_lang_Thread::thread_id(this->threadObj()));
1799 event.commit();
1800 }
1801
1802 // Call after last event on thread
1803 EVENT_THREAD_EXIT(this);
1804
1805 // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1806 // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1807 // is deprecated anyhow.
1808 { int count = 3;
1809 while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1810 EXCEPTION_MARK;
1811 JavaValue result(T_VOID);
1812 KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1813 JavaCalls::call_virtual(&result,
1814 threadObj, thread_klass,
1815 vmSymbols::exit_method_name(),
1816 vmSymbols::void_method_signature(),
1817 THREAD);
1818 CLEAR_PENDING_EXCEPTION;
1819 }
1820 }
1821
1822 // notify JVMTI
1823 if (JvmtiExport::should_post_thread_life()) {
1824 JvmtiExport::post_thread_end(this);
1825 }
1826
1827 // We have notified the agents that we are exiting, before we go on,
1828 // we must check for a pending external suspend request and honor it
1829 // in order to not surprise the thread that made the suspend request.
1830 while (true) {
1831 {
1832 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1833 if (!is_external_suspend()) {
1834 set_terminated(_thread_exiting);
1835 ThreadService::current_thread_exiting(this);
1836 break;
1837 }
1838 // Implied else:
1839 // Things get a little tricky here. We have a pending external
1840 // suspend request, but we are holding the SR_lock so we
1841 // can't just self-suspend. So we temporarily drop the lock
1842 // and then self-suspend.
1843 }
1844
1845 ThreadBlockInVM tbivm(this);
1846 java_suspend_self();
1847
1848 // We're done with this suspend request, but we have to loop around
1849 // and check again. Eventually we will get SR_lock without a pending
1850 // external suspend request and will be able to mark ourselves as
1851 // exiting.
1852 }
1853 // no more external suspends are allowed at this point
1854 } else {
1855 // before_exit() has already posted JVMTI THREAD_END events
1856 }
1857
1858 // Notify waiters on thread object. This has to be done after exit() is called
1859 // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1860 // group should have the destroyed bit set before waiters are notified).
1861 ensure_join(this);
1862 assert(!this->has_pending_exception(), "ensure_join should have cleared");
1863
1864 // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1865 // held by this thread must be released. A detach operation must only
1866 // get here if there are no Java frames on the stack. Therefore, any
1867 // owned monitors at this point MUST be JNI-acquired monitors which are
1868 // pre-inflated and in the monitor cache.
1869 //
1870 // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1871 if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1872 assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1873 ObjectSynchronizer::release_monitors_owned_by_thread(this);
1874 assert(!this->has_pending_exception(), "release_monitors should have cleared");
1875 }
1876
1877 // These things needs to be done while we are still a Java Thread. Make sure that thread
1878 // is in a consistent state, in case GC happens
1879 assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1880
1881 if (active_handles() != NULL) {
1882 JNIHandleBlock* block = active_handles();
1883 set_active_handles(NULL);
1884 JNIHandleBlock::release_block(block);
1885 }
1886
1887 if (free_handle_block() != NULL) {
1888 JNIHandleBlock* block = free_handle_block();
1889 set_free_handle_block(NULL);
1890 JNIHandleBlock::release_block(block);
1891 }
1892
1893 // These have to be removed while this is still a valid thread.
1894 remove_stack_guard_pages();
1895
1896 if (UseTLAB) {
1897 tlab().make_parsable(true); // retire TLAB
1898 }
1899
1900 if (JvmtiEnv::environments_might_exist()) {
1901 JvmtiExport::cleanup_thread(this);
1902 }
1903
1904 // We must flush any deferred card marks before removing a thread from
1905 // the list of active threads.
1906 Universe::heap()->flush_deferred_store_barrier(this);
1907 assert(deferred_card_mark().is_empty(), "Should have been flushed");
1908
1909 #if INCLUDE_ALL_GCS
1910 // We must flush the G1-related buffers before removing a thread
1911 // from the list of active threads. We must do this after any deferred
1912 // card marks have been flushed (above) so that any entries that are
1913 // added to the thread's dirty card queue as a result are not lost.
1914 if (UseG1GC) {
1915 flush_barrier_queues();
1916 }
1917 #endif // INCLUDE_ALL_GCS
1918
1919 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1920 Threads::remove(this);
1921 }
1922
1923 #if INCLUDE_ALL_GCS
1924 // Flush G1-related queues.
1925 void JavaThread::flush_barrier_queues() {
1926 satb_mark_queue().flush();
1927 dirty_card_queue().flush();
1928 }
1929
1930 void JavaThread::initialize_queues() {
1931 assert(!SafepointSynchronize::is_at_safepoint(),
1932 "we should not be at a safepoint");
1933
1934 ObjPtrQueue& satb_queue = satb_mark_queue();
1935 SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
1936 // The SATB queue should have been constructed with its active
1937 // field set to false.
1938 assert(!satb_queue.is_active(), "SATB queue should not be active");
1939 assert(satb_queue.is_empty(), "SATB queue should be empty");
1940 // If we are creating the thread during a marking cycle, we should
1941 // set the active field of the SATB queue to true.
1942 if (satb_queue_set.is_active()) {
1943 satb_queue.set_active(true);
1944 }
1945
1946 DirtyCardQueue& dirty_queue = dirty_card_queue();
1947 // The dirty card queue should have been constructed with its
1948 // active field set to true.
1949 assert(dirty_queue.is_active(), "dirty card queue should be active");
1950 }
1951 #endif // INCLUDE_ALL_GCS
1952
1953 void JavaThread::cleanup_failed_attach_current_thread() {
1954 if (get_thread_profiler() != NULL) {
1955 get_thread_profiler()->disengage();
1956 ResourceMark rm;
1957 get_thread_profiler()->print(get_thread_name());
1958 }
1959
1960 if (active_handles() != NULL) {
1961 JNIHandleBlock* block = active_handles();
1962 set_active_handles(NULL);
1963 JNIHandleBlock::release_block(block);
1964 }
1965
1966 if (free_handle_block() != NULL) {
1967 JNIHandleBlock* block = free_handle_block();
1968 set_free_handle_block(NULL);
1969 JNIHandleBlock::release_block(block);
1970 }
1971
1972 // These have to be removed while this is still a valid thread.
1973 remove_stack_guard_pages();
1974
1975 if (UseTLAB) {
1976 tlab().make_parsable(true); // retire TLAB, if any
1977 }
1978
1979 #if INCLUDE_ALL_GCS
1980 if (UseG1GC) {
1981 flush_barrier_queues();
1982 }
1983 #endif // INCLUDE_ALL_GCS
1984
1985 Threads::remove(this);
1986 delete this;
1987 }
1988
1989
1990
1991
1992 JavaThread* JavaThread::active() {
1993 Thread* thread = ThreadLocalStorage::thread();
1994 assert(thread != NULL, "just checking");
1995 if (thread->is_Java_thread()) {
1996 return (JavaThread*) thread;
1997 } else {
1998 assert(thread->is_VM_thread(), "this must be a vm thread");
1999 VM_Operation* op = ((VMThread*) thread)->vm_operation();
2000 JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
2001 assert(ret->is_Java_thread(), "must be a Java thread");
2002 return ret;
2003 }
2004 }
2005
2006 bool JavaThread::is_lock_owned(address adr) const {
2007 if (Thread::is_lock_owned(adr)) return true;
2008
2009 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2010 if (chunk->contains(adr)) return true;
2011 }
2012
2013 return false;
2014 }
2015
2016
2017 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
2018 chunk->set_next(monitor_chunks());
2019 set_monitor_chunks(chunk);
2020 }
2021
2022 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
2023 guarantee(monitor_chunks() != NULL, "must be non empty");
2024 if (monitor_chunks() == chunk) {
2025 set_monitor_chunks(chunk->next());
2026 } else {
2027 MonitorChunk* prev = monitor_chunks();
2028 while (prev->next() != chunk) prev = prev->next();
2029 prev->set_next(chunk->next());
2030 }
2031 }
2032
2033 // JVM support.
2034
2035 // Note: this function shouldn't block if it's called in
2036 // _thread_in_native_trans state (such as from
2037 // check_special_condition_for_native_trans()).
2038 void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
2039
2040 if (has_last_Java_frame() && has_async_condition()) {
2041 // If we are at a polling page safepoint (not a poll return)
2042 // then we must defer async exception because live registers
2043 // will be clobbered by the exception path. Poll return is
2044 // ok because the call we a returning from already collides
2045 // with exception handling registers and so there is no issue.
2046 // (The exception handling path kills call result registers but
2047 // this is ok since the exception kills the result anyway).
2048
2049 if (is_at_poll_safepoint()) {
2050 // if the code we are returning to has deoptimized we must defer
2051 // the exception otherwise live registers get clobbered on the
2052 // exception path before deoptimization is able to retrieve them.
2053 //
2054 RegisterMap map(this, false);
2055 frame caller_fr = last_frame().sender(&map);
2056 assert(caller_fr.is_compiled_frame(), "what?");
2057 if (caller_fr.is_deoptimized_frame()) {
2058 if (TraceExceptions) {
2059 ResourceMark rm;
2060 tty->print_cr("deferred async exception at compiled safepoint");
2061 }
2062 return;
2063 }
2064 }
2065 }
2066
2067 JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
2068 if (condition == _no_async_condition) {
2069 // Conditions have changed since has_special_runtime_exit_condition()
2070 // was called:
2071 // - if we were here only because of an external suspend request,
2072 // then that was taken care of above (or cancelled) so we are done
2073 // - if we were here because of another async request, then it has
2074 // been cleared between the has_special_runtime_exit_condition()
2075 // and now so again we are done
2076 return;
2077 }
2078
2079 // Check for pending async. exception
2080 if (_pending_async_exception != NULL) {
2081 // Only overwrite an already pending exception, if it is not a threadDeath.
2082 if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
2083
2084 // We cannot call Exceptions::_throw(...) here because we cannot block
2085 set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
2086
2087 if (TraceExceptions) {
2088 ResourceMark rm;
2089 tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
2090 if (has_last_Java_frame() ) {
2091 frame f = last_frame();
2092 tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
2093 }
2094 tty->print_cr(" of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2095 }
2096 _pending_async_exception = NULL;
2097 clear_has_async_exception();
2098 }
2099 }
2100
2101 if (check_unsafe_error &&
2102 condition == _async_unsafe_access_error && !has_pending_exception()) {
2103 condition = _no_async_condition; // done
2104 switch (thread_state()) {
2105 case _thread_in_vm:
2106 {
2107 JavaThread* THREAD = this;
2108 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2109 }
2110 case _thread_in_native:
2111 {
2112 ThreadInVMfromNative tiv(this);
2113 JavaThread* THREAD = this;
2114 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
2115 }
2116 case _thread_in_Java:
2117 {
2118 ThreadInVMfromJava tiv(this);
2119 JavaThread* THREAD = this;
2120 THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
2121 }
2122 default:
2123 ShouldNotReachHere();
2124 }
2125 }
2126
2127 assert(condition == _no_async_condition || has_pending_exception() ||
2128 (!check_unsafe_error && condition == _async_unsafe_access_error),
2129 "must have handled the async condition, if no exception");
2130 }
2131
2132 void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
2133 //
2134 // Check for pending external suspend. Internal suspend requests do
2135 // not use handle_special_runtime_exit_condition().
2136 // If JNIEnv proxies are allowed, don't self-suspend if the target
2137 // thread is not the current thread. In older versions of jdbx, jdbx
2138 // threads could call into the VM with another thread's JNIEnv so we
2139 // can be here operating on behalf of a suspended thread (4432884).
2140 bool do_self_suspend = is_external_suspend_with_lock();
2141 if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
2142 //
2143 // Because thread is external suspended the safepoint code will count
2144 // thread as at a safepoint. This can be odd because we can be here
2145 // as _thread_in_Java which would normally transition to _thread_blocked
2146 // at a safepoint. We would like to mark the thread as _thread_blocked
2147 // before calling java_suspend_self like all other callers of it but
2148 // we must then observe proper safepoint protocol. (We can't leave
2149 // _thread_blocked with a safepoint in progress). However we can be
2150 // here as _thread_in_native_trans so we can't use a normal transition
2151 // constructor/destructor pair because they assert on that type of
2152 // transition. We could do something like:
2153 //
2154 // JavaThreadState state = thread_state();
2155 // set_thread_state(_thread_in_vm);
2156 // {
2157 // ThreadBlockInVM tbivm(this);
2158 // java_suspend_self()
2159 // }
2160 // set_thread_state(_thread_in_vm_trans);
2161 // if (safepoint) block;
2162 // set_thread_state(state);
2163 //
2164 // but that is pretty messy. Instead we just go with the way the
2165 // code has worked before and note that this is the only path to
2166 // java_suspend_self that doesn't put the thread in _thread_blocked
2167 // mode.
2168
2169 frame_anchor()->make_walkable(this);
2170 java_suspend_self();
2171
2172 // We might be here for reasons in addition to the self-suspend request
2173 // so check for other async requests.
2174 }
2175
2176 if (check_asyncs) {
2177 check_and_handle_async_exceptions();
2178 }
2179 }
2180
2181 void JavaThread::send_thread_stop(oop java_throwable) {
2182 assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
2183 assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
2184 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
2185
2186 // Do not throw asynchronous exceptions against the compiler thread
2187 // (the compiler thread should not be a Java thread -- fix in 1.4.2)
2188 if (is_Compiler_thread()) return;
2189
2190 {
2191 // Actually throw the Throwable against the target Thread - however
2192 // only if there is no thread death exception installed already.
2193 if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
2194 // If the topmost frame is a runtime stub, then we are calling into
2195 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
2196 // must deoptimize the caller before continuing, as the compiled exception handler table
2197 // may not be valid
2198 if (has_last_Java_frame()) {
2199 frame f = last_frame();
2200 if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
2201 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2202 RegisterMap reg_map(this, UseBiasedLocking);
2203 frame compiled_frame = f.sender(®_map);
2204 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
2205 Deoptimization::deoptimize(this, compiled_frame, ®_map);
2206 }
2207 }
2208 }
2209
2210 // Set async. pending exception in thread.
2211 set_pending_async_exception(java_throwable);
2212
2213 if (TraceExceptions) {
2214 ResourceMark rm;
2215 tty->print_cr("Pending Async. exception installed of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
2216 }
2217 // for AbortVMOnException flag
2218 NOT_PRODUCT(Exceptions::debug_check_abort(InstanceKlass::cast(_pending_async_exception->klass())->external_name()));
2219 }
2220 }
2221
2222
2223 // Interrupt thread so it will wake up from a potential wait()
2224 Thread::interrupt(this);
2225 }
2226
2227 // External suspension mechanism.
2228 //
2229 // Tell the VM to suspend a thread when ever it knows that it does not hold on
2230 // to any VM_locks and it is at a transition
2231 // Self-suspension will happen on the transition out of the vm.
2232 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
2233 //
2234 // Guarantees on return:
2235 // + Target thread will not execute any new bytecode (that's why we need to
2236 // force a safepoint)
2237 // + Target thread will not enter any new monitors
2238 //
2239 void JavaThread::java_suspend() {
2240 { MutexLocker mu(Threads_lock);
2241 if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
2242 return;
2243 }
2244 }
2245
2246 { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2247 if (!is_external_suspend()) {
2248 // a racing resume has cancelled us; bail out now
2249 return;
2250 }
2251
2252 // suspend is done
2253 uint32_t debug_bits = 0;
2254 // Warning: is_ext_suspend_completed() may temporarily drop the
2255 // SR_lock to allow the thread to reach a stable thread state if
2256 // it is currently in a transient thread state.
2257 if (is_ext_suspend_completed(false /* !called_by_wait */,
2258 SuspendRetryDelay, &debug_bits) ) {
2259 return;
2260 }
2261 }
2262
2263 VM_ForceSafepoint vm_suspend;
2264 VMThread::execute(&vm_suspend);
2265 }
2266
2267 // Part II of external suspension.
2268 // A JavaThread self suspends when it detects a pending external suspend
2269 // request. This is usually on transitions. It is also done in places
2270 // where continuing to the next transition would surprise the caller,
2271 // e.g., monitor entry.
2272 //
2273 // Returns the number of times that the thread self-suspended.
2274 //
2275 // Note: DO NOT call java_suspend_self() when you just want to block current
2276 // thread. java_suspend_self() is the second stage of cooperative
2277 // suspension for external suspend requests and should only be used
2278 // to complete an external suspend request.
2279 //
2280 int JavaThread::java_suspend_self() {
2281 int ret = 0;
2282
2283 // we are in the process of exiting so don't suspend
2284 if (is_exiting()) {
2285 clear_external_suspend();
2286 return ret;
2287 }
2288
2289 assert(_anchor.walkable() ||
2290 (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
2291 "must have walkable stack");
2292
2293 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2294
2295 assert(!this->is_ext_suspended(),
2296 "a thread trying to self-suspend should not already be suspended");
2297
2298 if (this->is_suspend_equivalent()) {
2299 // If we are self-suspending as a result of the lifting of a
2300 // suspend equivalent condition, then the suspend_equivalent
2301 // flag is not cleared until we set the ext_suspended flag so
2302 // that wait_for_ext_suspend_completion() returns consistent
2303 // results.
2304 this->clear_suspend_equivalent();
2305 }
2306
2307 // A racing resume may have cancelled us before we grabbed SR_lock
2308 // above. Or another external suspend request could be waiting for us
2309 // by the time we return from SR_lock()->wait(). The thread
2310 // that requested the suspension may already be trying to walk our
2311 // stack and if we return now, we can change the stack out from under
2312 // it. This would be a "bad thing (TM)" and cause the stack walker
2313 // to crash. We stay self-suspended until there are no more pending
2314 // external suspend requests.
2315 while (is_external_suspend()) {
2316 ret++;
2317 this->set_ext_suspended();
2318
2319 // _ext_suspended flag is cleared by java_resume()
2320 while (is_ext_suspended()) {
2321 this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
2322 }
2323 }
2324
2325 return ret;
2326 }
2327
2328 #ifdef ASSERT
2329 // verify the JavaThread has not yet been published in the Threads::list, and
2330 // hence doesn't need protection from concurrent access at this stage
2331 void JavaThread::verify_not_published() {
2332 if (!Threads_lock->owned_by_self()) {
2333 MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
2334 assert( !Threads::includes(this),
2335 "java thread shouldn't have been published yet!");
2336 }
2337 else {
2338 assert( !Threads::includes(this),
2339 "java thread shouldn't have been published yet!");
2340 }
2341 }
2342 #endif
2343
2344 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2345 // progress or when _suspend_flags is non-zero.
2346 // Current thread needs to self-suspend if there is a suspend request and/or
2347 // block if a safepoint is in progress.
2348 // Async exception ISN'T checked.
2349 // Note only the ThreadInVMfromNative transition can call this function
2350 // directly and when thread state is _thread_in_native_trans
2351 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2352 assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2353
2354 JavaThread *curJT = JavaThread::current();
2355 bool do_self_suspend = thread->is_external_suspend();
2356
2357 assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2358
2359 // If JNIEnv proxies are allowed, don't self-suspend if the target
2360 // thread is not the current thread. In older versions of jdbx, jdbx
2361 // threads could call into the VM with another thread's JNIEnv so we
2362 // can be here operating on behalf of a suspended thread (4432884).
2363 if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
2364 JavaThreadState state = thread->thread_state();
2365
2366 // We mark this thread_blocked state as a suspend-equivalent so
2367 // that a caller to is_ext_suspend_completed() won't be confused.
2368 // The suspend-equivalent state is cleared by java_suspend_self().
2369 thread->set_suspend_equivalent();
2370
2371 // If the safepoint code sees the _thread_in_native_trans state, it will
2372 // wait until the thread changes to other thread state. There is no
2373 // guarantee on how soon we can obtain the SR_lock and complete the
2374 // self-suspend request. It would be a bad idea to let safepoint wait for
2375 // too long. Temporarily change the state to _thread_blocked to
2376 // let the VM thread know that this thread is ready for GC. The problem
2377 // of changing thread state is that safepoint could happen just after
2378 // java_suspend_self() returns after being resumed, and VM thread will
2379 // see the _thread_blocked state. We must check for safepoint
2380 // after restoring the state and make sure we won't leave while a safepoint
2381 // is in progress.
2382 thread->set_thread_state(_thread_blocked);
2383 thread->java_suspend_self();
2384 thread->set_thread_state(state);
2385 // Make sure new state is seen by VM thread
2386 if (os::is_MP()) {
2387 if (UseMembar) {
2388 // Force a fence between the write above and read below
2389 OrderAccess::fence();
2390 } else {
2391 // Must use this rather than serialization page in particular on Windows
2392 InterfaceSupport::serialize_memory(thread);
2393 }
2394 }
2395 }
2396
2397 if (SafepointSynchronize::do_call_back()) {
2398 // If we are safepointing, then block the caller which may not be
2399 // the same as the target thread (see above).
2400 SafepointSynchronize::block(curJT);
2401 }
2402
2403 if (thread->is_deopt_suspend()) {
2404 thread->clear_deopt_suspend();
2405 RegisterMap map(thread, false);
2406 frame f = thread->last_frame();
2407 while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
2408 f = f.sender(&map);
2409 }
2410 if (f.id() == thread->must_deopt_id()) {
2411 thread->clear_must_deopt_id();
2412 f.deoptimize(thread);
2413 } else {
2414 fatal("missed deoptimization!");
2415 }
2416 }
2417 }
2418
2419 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2420 // progress or when _suspend_flags is non-zero.
2421 // Current thread needs to self-suspend if there is a suspend request and/or
2422 // block if a safepoint is in progress.
2423 // Also check for pending async exception (not including unsafe access error).
2424 // Note only the native==>VM/Java barriers can call this function and when
2425 // thread state is _thread_in_native_trans.
2426 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
2427 check_safepoint_and_suspend_for_native_trans(thread);
2428
2429 if (thread->has_async_exception()) {
2430 // We are in _thread_in_native_trans state, don't handle unsafe
2431 // access error since that may block.
2432 thread->check_and_handle_async_exceptions(false);
2433 }
2434 }
2435
2436 // This is a variant of the normal
2437 // check_special_condition_for_native_trans with slightly different
2438 // semantics for use by critical native wrappers. It does all the
2439 // normal checks but also performs the transition back into
2440 // thread_in_Java state. This is required so that critical natives
2441 // can potentially block and perform a GC if they are the last thread
2442 // exiting the GC_locker.
2443 void JavaThread::check_special_condition_for_native_trans_and_transition(JavaThread *thread) {
2444 check_special_condition_for_native_trans(thread);
2445
2446 // Finish the transition
2447 thread->set_thread_state(_thread_in_Java);
2448
2449 if (thread->do_critical_native_unlock()) {
2450 ThreadInVMfromJavaNoAsyncException tiv(thread);
2451 GC_locker::unlock_critical(thread);
2452 thread->clear_critical_native_unlock();
2453 }
2454 }
2455
2456 // We need to guarantee the Threads_lock here, since resumes are not
2457 // allowed during safepoint synchronization
2458 // Can only resume from an external suspension
2459 void JavaThread::java_resume() {
2460 assert_locked_or_safepoint(Threads_lock);
2461
2462 // Sanity check: thread is gone, has started exiting or the thread
2463 // was not externally suspended.
2464 if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
2465 return;
2466 }
2467
2468 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2469
2470 clear_external_suspend();
2471
2472 if (is_ext_suspended()) {
2473 clear_ext_suspended();
2474 SR_lock()->notify_all();
2475 }
2476 }
2477
2478 void JavaThread::create_stack_guard_pages() {
2479 if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
2480 address low_addr = stack_base() - stack_size();
2481 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2482
2483 int allocate = os::allocate_stack_guard_pages();
2484 // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
2485
2486 if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) {
2487 warning("Attempt to allocate stack guard pages failed.");
2488 return;
2489 }
2490
2491 if (os::guard_memory((char *) low_addr, len)) {
2492 _stack_guard_state = stack_guard_enabled;
2493 } else {
2494 warning("Attempt to protect stack guard pages failed.");
2495 if (os::uncommit_memory((char *) low_addr, len)) {
2496 warning("Attempt to deallocate stack guard pages failed.");
2497 }
2498 }
2499 }
2500
2501 void JavaThread::remove_stack_guard_pages() {
2502 assert(Thread::current() == this, "from different thread");
2503 if (_stack_guard_state == stack_guard_unused) return;
2504 address low_addr = stack_base() - stack_size();
2505 size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
2506
2507 if (os::allocate_stack_guard_pages()) {
2508 if (os::remove_stack_guard_pages((char *) low_addr, len)) {
2509 _stack_guard_state = stack_guard_unused;
2510 } else {
2511 warning("Attempt to deallocate stack guard pages failed.");
2512 }
2513 } else {
2514 if (_stack_guard_state == stack_guard_unused) return;
2515 if (os::unguard_memory((char *) low_addr, len)) {
2516 _stack_guard_state = stack_guard_unused;
2517 } else {
2518 warning("Attempt to unprotect stack guard pages failed.");
2519 }
2520 }
2521 }
2522
2523 void JavaThread::enable_stack_yellow_zone() {
2524 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2525 assert(_stack_guard_state != stack_guard_enabled, "already enabled");
2526
2527 // The base notation is from the stacks point of view, growing downward.
2528 // We need to adjust it to work correctly with guard_memory()
2529 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2530
2531 guarantee(base < stack_base(),"Error calculating stack yellow zone");
2532 guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
2533
2534 if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
2535 _stack_guard_state = stack_guard_enabled;
2536 } else {
2537 warning("Attempt to guard stack yellow zone failed.");
2538 }
2539 enable_register_stack_guard();
2540 }
2541
2542 void JavaThread::disable_stack_yellow_zone() {
2543 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2544 assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
2545
2546 // Simply return if called for a thread that does not use guard pages.
2547 if (_stack_guard_state == stack_guard_unused) return;
2548
2549 // The base notation is from the stacks point of view, growing downward.
2550 // We need to adjust it to work correctly with guard_memory()
2551 address base = stack_yellow_zone_base() - stack_yellow_zone_size();
2552
2553 if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
2554 _stack_guard_state = stack_guard_yellow_disabled;
2555 } else {
2556 warning("Attempt to unguard stack yellow zone failed.");
2557 }
2558 disable_register_stack_guard();
2559 }
2560
2561 void JavaThread::enable_stack_red_zone() {
2562 // The base notation is from the stacks point of view, growing downward.
2563 // We need to adjust it to work correctly with guard_memory()
2564 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2565 address base = stack_red_zone_base() - stack_red_zone_size();
2566
2567 guarantee(base < stack_base(),"Error calculating stack red zone");
2568 guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
2569
2570 if(!os::guard_memory((char *) base, stack_red_zone_size())) {
2571 warning("Attempt to guard stack red zone failed.");
2572 }
2573 }
2574
2575 void JavaThread::disable_stack_red_zone() {
2576 // The base notation is from the stacks point of view, growing downward.
2577 // We need to adjust it to work correctly with guard_memory()
2578 assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
2579 address base = stack_red_zone_base() - stack_red_zone_size();
2580 if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
2581 warning("Attempt to unguard stack red zone failed.");
2582 }
2583 }
2584
2585 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
2586 // ignore is there is no stack
2587 if (!has_last_Java_frame()) return;
2588 // traverse the stack frames. Starts from top frame.
2589 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2590 frame* fr = fst.current();
2591 f(fr, fst.register_map());
2592 }
2593 }
2594
2595
2596 #ifndef PRODUCT
2597 // Deoptimization
2598 // Function for testing deoptimization
2599 void JavaThread::deoptimize() {
2600 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2601 StackFrameStream fst(this, UseBiasedLocking);
2602 bool deopt = false; // Dump stack only if a deopt actually happens.
2603 bool only_at = strlen(DeoptimizeOnlyAt) > 0;
2604 // Iterate over all frames in the thread and deoptimize
2605 for(; !fst.is_done(); fst.next()) {
2606 if(fst.current()->can_be_deoptimized()) {
2607
2608 if (only_at) {
2609 // Deoptimize only at particular bcis. DeoptimizeOnlyAt
2610 // consists of comma or carriage return separated numbers so
2611 // search for the current bci in that string.
2612 address pc = fst.current()->pc();
2613 nmethod* nm = (nmethod*) fst.current()->cb();
2614 ScopeDesc* sd = nm->scope_desc_at( pc);
2615 char buffer[8];
2616 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
2617 size_t len = strlen(buffer);
2618 const char * found = strstr(DeoptimizeOnlyAt, buffer);
2619 while (found != NULL) {
2620 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
2621 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
2622 // Check that the bci found is bracketed by terminators.
2623 break;
2624 }
2625 found = strstr(found + 1, buffer);
2626 }
2627 if (!found) {
2628 continue;
2629 }
2630 }
2631
2632 if (DebugDeoptimization && !deopt) {
2633 deopt = true; // One-time only print before deopt
2634 tty->print_cr("[BEFORE Deoptimization]");
2635 trace_frames();
2636 trace_stack();
2637 }
2638 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2639 }
2640 }
2641
2642 if (DebugDeoptimization && deopt) {
2643 tty->print_cr("[AFTER Deoptimization]");
2644 trace_frames();
2645 }
2646 }
2647
2648
2649 // Make zombies
2650 void JavaThread::make_zombies() {
2651 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2652 if (fst.current()->can_be_deoptimized()) {
2653 // it is a Java nmethod
2654 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
2655 nm->make_not_entrant();
2656 }
2657 }
2658 }
2659 #endif // PRODUCT
2660
2661
2662 void JavaThread::deoptimized_wrt_marked_nmethods() {
2663 if (!has_last_Java_frame()) return;
2664 // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
2665 StackFrameStream fst(this, UseBiasedLocking);
2666 for(; !fst.is_done(); fst.next()) {
2667 if (fst.current()->should_be_deoptimized()) {
2668 if (LogCompilation && xtty != NULL) {
2669 nmethod* nm = fst.current()->cb()->as_nmethod_or_null();
2670 xtty->elem("deoptimized thread='" UINTX_FORMAT "' compile_id='%d'",
2671 this->name(), nm != NULL ? nm->compile_id() : -1);
2672 }
2673
2674 Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
2675 }
2676 }
2677 }
2678
2679
2680 // GC support
2681 static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
2682
2683 void JavaThread::gc_epilogue() {
2684 frames_do(frame_gc_epilogue);
2685 }
2686
2687
2688 static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
2689
2690 void JavaThread::gc_prologue() {
2691 frames_do(frame_gc_prologue);
2692 }
2693
2694 // If the caller is a NamedThread, then remember, in the current scope,
2695 // the given JavaThread in its _processed_thread field.
2696 class RememberProcessedThread: public StackObj {
2697 NamedThread* _cur_thr;
2698 public:
2699 RememberProcessedThread(JavaThread* jthr) {
2700 Thread* thread = Thread::current();
2701 if (thread->is_Named_thread()) {
2702 _cur_thr = (NamedThread *)thread;
2703 _cur_thr->set_processed_thread(jthr);
2704 } else {
2705 _cur_thr = NULL;
2706 }
2707 }
2708
2709 ~RememberProcessedThread() {
2710 if (_cur_thr) {
2711 _cur_thr->set_processed_thread(NULL);
2712 }
2713 }
2714 };
2715
2716 void JavaThread::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) {
2717 // Verify that the deferred card marks have been flushed.
2718 assert(deferred_card_mark().is_empty(), "Should be empty during GC");
2719
2720 // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
2721 // since there may be more than one thread using each ThreadProfiler.
2722
2723 // Traverse the GCHandles
2724 Thread::oops_do(f, cld_f, cf);
2725
2726 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2727 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2728
2729 if (has_last_Java_frame()) {
2730 // Record JavaThread to GC thread
2731 RememberProcessedThread rpt(this);
2732
2733 // Traverse the privileged stack
2734 if (_privileged_stack_top != NULL) {
2735 _privileged_stack_top->oops_do(f);
2736 }
2737
2738 // traverse the registered growable array
2739 if (_array_for_gc != NULL) {
2740 for (int index = 0; index < _array_for_gc->length(); index++) {
2741 f->do_oop(_array_for_gc->adr_at(index));
2742 }
2743 }
2744
2745 // Traverse the monitor chunks
2746 for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
2747 chunk->oops_do(f);
2748 }
2749
2750 // Traverse the execution stack
2751 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2752 fst.current()->oops_do(f, cld_f, cf, fst.register_map());
2753 }
2754 }
2755
2756 // callee_target is never live across a gc point so NULL it here should
2757 // it still contain a methdOop.
2758
2759 set_callee_target(NULL);
2760
2761 assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
2762 // If we have deferred set_locals there might be oops waiting to be
2763 // written
2764 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
2765 if (list != NULL) {
2766 for (int i = 0; i < list->length(); i++) {
2767 list->at(i)->oops_do(f);
2768 }
2769 }
2770
2771 // Traverse instance variables at the end since the GC may be moving things
2772 // around using this function
2773 f->do_oop((oop*) &_threadObj);
2774 f->do_oop((oop*) &_vm_result);
2775 f->do_oop((oop*) &_exception_oop);
2776 f->do_oop((oop*) &_pending_async_exception);
2777
2778 if (jvmti_thread_state() != NULL) {
2779 jvmti_thread_state()->oops_do(f);
2780 }
2781 }
2782
2783 void JavaThread::nmethods_do(CodeBlobClosure* cf) {
2784 Thread::nmethods_do(cf); // (super method is a no-op)
2785
2786 assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
2787 (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
2788
2789 if (has_last_Java_frame()) {
2790 // Traverse the execution stack
2791 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2792 fst.current()->nmethods_do(cf);
2793 }
2794 }
2795 }
2796
2797 void JavaThread::metadata_do(void f(Metadata*)) {
2798 Thread::metadata_do(f);
2799 if (has_last_Java_frame()) {
2800 // Traverse the execution stack to call f() on the methods in the stack
2801 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
2802 fst.current()->metadata_do(f);
2803 }
2804 } else if (is_Compiler_thread()) {
2805 // need to walk ciMetadata in current compile tasks to keep alive.
2806 CompilerThread* ct = (CompilerThread*)this;
2807 if (ct->env() != NULL) {
2808 ct->env()->metadata_do(f);
2809 }
2810 }
2811 }
2812
2813 // Printing
2814 const char* _get_thread_state_name(JavaThreadState _thread_state) {
2815 switch (_thread_state) {
2816 case _thread_uninitialized: return "_thread_uninitialized";
2817 case _thread_new: return "_thread_new";
2818 case _thread_new_trans: return "_thread_new_trans";
2819 case _thread_in_native: return "_thread_in_native";
2820 case _thread_in_native_trans: return "_thread_in_native_trans";
2821 case _thread_in_vm: return "_thread_in_vm";
2822 case _thread_in_vm_trans: return "_thread_in_vm_trans";
2823 case _thread_in_Java: return "_thread_in_Java";
2824 case _thread_in_Java_trans: return "_thread_in_Java_trans";
2825 case _thread_blocked: return "_thread_blocked";
2826 case _thread_blocked_trans: return "_thread_blocked_trans";
2827 default: return "unknown thread state";
2828 }
2829 }
2830
2831 #ifndef PRODUCT
2832 void JavaThread::print_thread_state_on(outputStream *st) const {
2833 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
2834 };
2835 void JavaThread::print_thread_state() const {
2836 print_thread_state_on(tty);
2837 };
2838 #endif // PRODUCT
2839
2840 // Called by Threads::print() for VM_PrintThreads operation
2841 void JavaThread::print_on(outputStream *st) const {
2842 st->print("\"%s\" ", get_thread_name());
2843 oop thread_oop = threadObj();
2844 if (thread_oop != NULL) {
2845 st->print("#" INT64_FORMAT " ", java_lang_Thread::thread_id(thread_oop));
2846 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
2847 st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
2848 }
2849 Thread::print_on(st);
2850 // print guess for valid stack memory region (assume 4K pages); helps lock debugging
2851 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
2852 if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
2853 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
2854 }
2855 #ifndef PRODUCT
2856 print_thread_state_on(st);
2857 _safepoint_state->print_on(st);
2858 #endif // PRODUCT
2859 }
2860
2861 // Called by fatal error handler. The difference between this and
2862 // JavaThread::print() is that we can't grab lock or allocate memory.
2863 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2864 st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2865 oop thread_obj = threadObj();
2866 if (thread_obj != NULL) {
2867 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2868 }
2869 st->print(" [");
2870 st->print("%s", _get_thread_state_name(_thread_state));
2871 if (osthread()) {
2872 st->print(", id=%d", osthread()->thread_id());
2873 }
2874 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2875 _stack_base - _stack_size, _stack_base);
2876 st->print("]");
2877 return;
2878 }
2879
2880 // Verification
2881
2882 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2883
2884 void JavaThread::verify() {
2885 // Verify oops in the thread.
2886 oops_do(&VerifyOopClosure::verify_oop, NULL, NULL);
2887
2888 // Verify the stack frames.
2889 frames_do(frame_verify);
2890 }
2891
2892 // CR 6300358 (sub-CR 2137150)
2893 // Most callers of this method assume that it can't return NULL but a
2894 // thread may not have a name whilst it is in the process of attaching to
2895 // the VM - see CR 6412693, and there are places where a JavaThread can be
2896 // seen prior to having it's threadObj set (eg JNI attaching threads and
2897 // if vm exit occurs during initialization). These cases can all be accounted
2898 // for such that this method never returns NULL.
2899 const char* JavaThread::get_thread_name() const {
2900 #ifdef ASSERT
2901 // early safepoints can hit while current thread does not yet have TLS
2902 if (!SafepointSynchronize::is_at_safepoint()) {
2903 Thread *cur = Thread::current();
2904 if (!(cur->is_Java_thread() && cur == this)) {
2905 // Current JavaThreads are allowed to get their own name without
2906 // the Threads_lock.
2907 assert_locked_or_safepoint(Threads_lock);
2908 }
2909 }
2910 #endif // ASSERT
2911 return get_thread_name_string();
2912 }
2913
2914 // Returns a non-NULL representation of this thread's name, or a suitable
2915 // descriptive string if there is no set name
2916 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
2917 const char* name_str;
2918 oop thread_obj = threadObj();
2919 if (thread_obj != NULL) {
2920 typeArrayOop name = java_lang_Thread::name(thread_obj);
2921 if (name != NULL) {
2922 if (buf == NULL) {
2923 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2924 }
2925 else {
2926 name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
2927 }
2928 }
2929 else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
2930 name_str = "<no-name - thread is attaching>";
2931 }
2932 else {
2933 name_str = Thread::name();
2934 }
2935 }
2936 else {
2937 name_str = Thread::name();
2938 }
2939 assert(name_str != NULL, "unexpected NULL thread name");
2940 return name_str;
2941 }
2942
2943
2944 const char* JavaThread::get_threadgroup_name() const {
2945 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2946 oop thread_obj = threadObj();
2947 if (thread_obj != NULL) {
2948 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2949 if (thread_group != NULL) {
2950 typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
2951 // ThreadGroup.name can be null
2952 if (name != NULL) {
2953 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2954 return str;
2955 }
2956 }
2957 }
2958 return NULL;
2959 }
2960
2961 const char* JavaThread::get_parent_name() const {
2962 debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
2963 oop thread_obj = threadObj();
2964 if (thread_obj != NULL) {
2965 oop thread_group = java_lang_Thread::threadGroup(thread_obj);
2966 if (thread_group != NULL) {
2967 oop parent = java_lang_ThreadGroup::parent(thread_group);
2968 if (parent != NULL) {
2969 typeArrayOop name = java_lang_ThreadGroup::name(parent);
2970 // ThreadGroup.name can be null
2971 if (name != NULL) {
2972 const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
2973 return str;
2974 }
2975 }
2976 }
2977 }
2978 return NULL;
2979 }
2980
2981 ThreadPriority JavaThread::java_priority() const {
2982 oop thr_oop = threadObj();
2983 if (thr_oop == NULL) return NormPriority; // Bootstrapping
2984 ThreadPriority priority = java_lang_Thread::priority(thr_oop);
2985 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
2986 return priority;
2987 }
2988
2989 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
2990
2991 assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
2992 // Link Java Thread object <-> C++ Thread
2993
2994 // Get the C++ thread object (an oop) from the JNI handle (a jthread)
2995 // and put it into a new Handle. The Handle "thread_oop" can then
2996 // be used to pass the C++ thread object to other methods.
2997
2998 // Set the Java level thread object (jthread) field of the
2999 // new thread (a JavaThread *) to C++ thread object using the
3000 // "thread_oop" handle.
3001
3002 // Set the thread field (a JavaThread *) of the
3003 // oop representing the java_lang_Thread to the new thread (a JavaThread *).
3004
3005 Handle thread_oop(Thread::current(),
3006 JNIHandles::resolve_non_null(jni_thread));
3007 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
3008 "must be initialized");
3009 set_threadObj(thread_oop());
3010 java_lang_Thread::set_thread(thread_oop(), this);
3011
3012 if (prio == NoPriority) {
3013 prio = java_lang_Thread::priority(thread_oop());
3014 assert(prio != NoPriority, "A valid priority should be present");
3015 }
3016
3017 // Push the Java priority down to the native thread; needs Threads_lock
3018 Thread::set_priority(this, prio);
3019
3020 // Add the new thread to the Threads list and set it in motion.
3021 // We must have threads lock in order to call Threads::add.
3022 // It is crucial that we do not block before the thread is
3023 // added to the Threads list for if a GC happens, then the java_thread oop
3024 // will not be visited by GC.
3025 Threads::add(this);
3026 }
3027
3028 oop JavaThread::current_park_blocker() {
3029 // Support for JSR-166 locks
3030 oop thread_oop = threadObj();
3031 if (thread_oop != NULL &&
3032 JDK_Version::current().supports_thread_park_blocker()) {
3033 return java_lang_Thread::park_blocker(thread_oop);
3034 }
3035 return NULL;
3036 }
3037
3038
3039 void JavaThread::print_stack_on(outputStream* st) {
3040 if (!has_last_Java_frame()) return;
3041 ResourceMark rm;
3042 HandleMark hm;
3043
3044 RegisterMap reg_map(this);
3045 vframe* start_vf = last_java_vframe(®_map);
3046 int count = 0;
3047 for (vframe* f = start_vf; f; f = f->sender() ) {
3048 if (f->is_java_frame()) {
3049 javaVFrame* jvf = javaVFrame::cast(f);
3050 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
3051
3052 // Print out lock information
3053 if (JavaMonitorsInStackTrace) {
3054 jvf->print_lock_info_on(st, count);
3055 }
3056 } else {
3057 // Ignore non-Java frames
3058 }
3059
3060 // Bail-out case for too deep stacks
3061 count++;
3062 if (MaxJavaStackTraceDepth == count) return;
3063 }
3064 }
3065
3066
3067 // JVMTI PopFrame support
3068 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
3069 assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
3070 if (in_bytes(size_in_bytes) != 0) {
3071 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
3072 _popframe_preserved_args_size = in_bytes(size_in_bytes);
3073 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
3074 }
3075 }
3076
3077 void* JavaThread::popframe_preserved_args() {
3078 return _popframe_preserved_args;
3079 }
3080
3081 ByteSize JavaThread::popframe_preserved_args_size() {
3082 return in_ByteSize(_popframe_preserved_args_size);
3083 }
3084
3085 WordSize JavaThread::popframe_preserved_args_size_in_words() {
3086 int sz = in_bytes(popframe_preserved_args_size());
3087 assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
3088 return in_WordSize(sz / wordSize);
3089 }
3090
3091 void JavaThread::popframe_free_preserved_args() {
3092 assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
3093 FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args, mtThread);
3094 _popframe_preserved_args = NULL;
3095 _popframe_preserved_args_size = 0;
3096 }
3097
3098 #ifndef PRODUCT
3099
3100 void JavaThread::trace_frames() {
3101 tty->print_cr("[Describe stack]");
3102 int frame_no = 1;
3103 for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
3104 tty->print(" %d. ", frame_no++);
3105 fst.current()->print_value_on(tty,this);
3106 tty->cr();
3107 }
3108 }
3109
3110 class PrintAndVerifyOopClosure: public OopClosure {
3111 protected:
3112 template <class T> inline void do_oop_work(T* p) {
3113 oop obj = oopDesc::load_decode_heap_oop(p);
3114 if (obj == NULL) return;
3115 tty->print(INTPTR_FORMAT ": ", p);
3116 if (obj->is_oop_or_null()) {
3117 if (obj->is_objArray()) {
3118 tty->print_cr("valid objArray: " INTPTR_FORMAT, (oopDesc*) obj);
3119 } else {
3120 obj->print();
3121 }
3122 } else {
3123 tty->print_cr("invalid oop: " INTPTR_FORMAT, (oopDesc*) obj);
3124 }
3125 tty->cr();
3126 }
3127 public:
3128 virtual void do_oop(oop* p) { do_oop_work(p); }
3129 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
3130 };
3131
3132
3133 static void oops_print(frame* f, const RegisterMap *map) {
3134 PrintAndVerifyOopClosure print;
3135 f->print_value();
3136 f->oops_do(&print, NULL, NULL, (RegisterMap*)map);
3137 }
3138
3139 // Print our all the locations that contain oops and whether they are
3140 // valid or not. This useful when trying to find the oldest frame
3141 // where an oop has gone bad since the frame walk is from youngest to
3142 // oldest.
3143 void JavaThread::trace_oops() {
3144 tty->print_cr("[Trace oops]");
3145 frames_do(oops_print);
3146 }
3147
3148
3149 #ifdef ASSERT
3150 // Print or validate the layout of stack frames
3151 void JavaThread::print_frame_layout(int depth, bool validate_only) {
3152 ResourceMark rm;
3153 PRESERVE_EXCEPTION_MARK;
3154 FrameValues values;
3155 int frame_no = 0;
3156 for(StackFrameStream fst(this, false); !fst.is_done(); fst.next()) {
3157 fst.current()->describe(values, ++frame_no);
3158 if (depth == frame_no) break;
3159 }
3160 if (validate_only) {
3161 values.validate();
3162 } else {
3163 tty->print_cr("[Describe stack layout]");
3164 values.print(this);
3165 }
3166 }
3167 #endif
3168
3169 void JavaThread::trace_stack_from(vframe* start_vf) {
3170 ResourceMark rm;
3171 int vframe_no = 1;
3172 for (vframe* f = start_vf; f; f = f->sender() ) {
3173 if (f->is_java_frame()) {
3174 javaVFrame::cast(f)->print_activation(vframe_no++);
3175 } else {
3176 f->print();
3177 }
3178 if (vframe_no > StackPrintLimit) {
3179 tty->print_cr("...<more frames>...");
3180 return;
3181 }
3182 }
3183 }
3184
3185
3186 void JavaThread::trace_stack() {
3187 if (!has_last_Java_frame()) return;
3188 ResourceMark rm;
3189 HandleMark hm;
3190 RegisterMap reg_map(this);
3191 trace_stack_from(last_java_vframe(®_map));
3192 }
3193
3194
3195 #endif // PRODUCT
3196
3197
3198 javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
3199 assert(reg_map != NULL, "a map must be given");
3200 frame f = last_frame();
3201 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
3202 if (vf->is_java_frame()) return javaVFrame::cast(vf);
3203 }
3204 return NULL;
3205 }
3206
3207
3208 Klass* JavaThread::security_get_caller_class(int depth) {
3209 vframeStream vfst(this);
3210 vfst.security_get_caller_frame(depth);
3211 if (!vfst.at_end()) {
3212 return vfst.method()->method_holder();
3213 }
3214 return NULL;
3215 }
3216
3217 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
3218 assert(thread->is_Compiler_thread(), "must be compiler thread");
3219 CompileBroker::compiler_thread_loop();
3220 }
3221
3222 // Create a CompilerThread
3223 CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
3224 : JavaThread(&compiler_thread_entry) {
3225 _env = NULL;
3226 _log = NULL;
3227 _task = NULL;
3228 _queue = queue;
3229 _counters = counters;
3230 _buffer_blob = NULL;
3231 _scanned_nmethod = NULL;
3232
3233 #ifndef PRODUCT
3234 _ideal_graph_printer = NULL;
3235 #endif
3236 }
3237
3238 void CompilerThread::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) {
3239 JavaThread::oops_do(f, cld_f, cf);
3240 if (_scanned_nmethod != NULL && cf != NULL) {
3241 // Safepoints can occur when the sweeper is scanning an nmethod so
3242 // process it here to make sure it isn't unloaded in the middle of
3243 // a scan.
3244 cf->do_code_blob(_scanned_nmethod);
3245 }
3246 }
3247
3248 // ======= Threads ========
3249
3250 // The Threads class links together all active threads, and provides
3251 // operations over all threads. It is protected by its own Mutex
3252 // lock, which is also used in other contexts to protect thread
3253 // operations from having the thread being operated on from exiting
3254 // and going away unexpectedly (e.g., safepoint synchronization)
3255
3256 JavaThread* Threads::_thread_list = NULL;
3257 int Threads::_number_of_threads = 0;
3258 int Threads::_number_of_non_daemon_threads = 0;
3259 int Threads::_return_code = 0;
3260 size_t JavaThread::_stack_size_at_create = 0;
3261 #ifdef ASSERT
3262 bool Threads::_vm_complete = false;
3263 #endif
3264
3265 // All JavaThreads
3266 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
3267
3268 void os_stream();
3269
3270 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
3271 void Threads::threads_do(ThreadClosure* tc) {
3272 assert_locked_or_safepoint(Threads_lock);
3273 // ALL_JAVA_THREADS iterates through all JavaThreads
3274 ALL_JAVA_THREADS(p) {
3275 tc->do_thread(p);
3276 }
3277 // Someday we could have a table or list of all non-JavaThreads.
3278 // For now, just manually iterate through them.
3279 tc->do_thread(VMThread::vm_thread());
3280 Universe::heap()->gc_threads_do(tc);
3281 WatcherThread *wt = WatcherThread::watcher_thread();
3282 // Strictly speaking, the following NULL check isn't sufficient to make sure
3283 // the data for WatcherThread is still valid upon being examined. However,
3284 // considering that WatchThread terminates when the VM is on the way to
3285 // exit at safepoint, the chance of the above is extremely small. The right
3286 // way to prevent termination of WatcherThread would be to acquire
3287 // Terminator_lock, but we can't do that without violating the lock rank
3288 // checking in some cases.
3289 if (wt != NULL)
3290 tc->do_thread(wt);
3291
3292 // If CompilerThreads ever become non-JavaThreads, add them here
3293 }
3294
3295 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
3296
3297 extern void JDK_Version_init();
3298
3299 // Check version
3300 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
3301
3302 // Initialize the output stream module
3303 ostream_init();
3304
3305 // Process java launcher properties.
3306 Arguments::process_sun_java_launcher_properties(args);
3307
3308 // Initialize the os module before using TLS
3309 os::init();
3310
3311 // Initialize system properties.
3312 Arguments::init_system_properties();
3313
3314 // So that JDK version can be used as a discrimintor when parsing arguments
3315 JDK_Version_init();
3316
3317 // Update/Initialize System properties after JDK version number is known
3318 Arguments::init_version_specific_system_properties();
3319
3320 // Parse arguments
3321 jint parse_result = Arguments::parse(args);
3322 if (parse_result != JNI_OK) return parse_result;
3323
3324 if (PauseAtStartup) {
3325 os::pause();
3326 }
3327
3328 #ifndef USDT2
3329 HS_DTRACE_PROBE(hotspot, vm__init__begin);
3330 #else /* USDT2 */
3331 HOTSPOT_VM_INIT_BEGIN();
3332 #endif /* USDT2 */
3333
3334 // Record VM creation timing statistics
3335 TraceVmCreationTime create_vm_timer;
3336 create_vm_timer.start();
3337
3338 // Timing (must come after argument parsing)
3339 TraceTime timer("Create VM", TraceStartupTime);
3340
3341 // Initialize the os module after parsing the args
3342 jint os_init_2_result = os::init_2();
3343 if (os_init_2_result != JNI_OK) return os_init_2_result;
3344
3345 jint adjust_after_os_result = Arguments::adjust_after_os();
3346 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
3347
3348 // intialize TLS
3349 ThreadLocalStorage::init();
3350
3351 // Bootstrap native memory tracking, so it can start recording memory
3352 // activities before worker thread is started. This is the first phase
3353 // of bootstrapping, VM is currently running in single-thread mode.
3354 MemTracker::bootstrap_single_thread();
3355
3356 // Initialize output stream logging
3357 ostream_init_log();
3358
3359 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
3360 // Must be before create_vm_init_agents()
3361 if (Arguments::init_libraries_at_startup()) {
3362 convert_vm_init_libraries_to_agents();
3363 }
3364
3365 // Launch -agentlib/-agentpath and converted -Xrun agents
3366 if (Arguments::init_agents_at_startup()) {
3367 create_vm_init_agents();
3368 }
3369
3370 // Initialize Threads state
3371 _thread_list = NULL;
3372 _number_of_threads = 0;
3373 _number_of_non_daemon_threads = 0;
3374
3375 // Initialize global data structures and create system classes in heap
3376 vm_init_globals();
3377
3378 // Attach the main thread to this os thread
3379 JavaThread* main_thread = new JavaThread();
3380 main_thread->set_thread_state(_thread_in_vm);
3381 // must do this before set_active_handles and initialize_thread_local_storage
3382 // Note: on solaris initialize_thread_local_storage() will (indirectly)
3383 // change the stack size recorded here to one based on the java thread
3384 // stacksize. This adjusted size is what is used to figure the placement
3385 // of the guard pages.
3386 main_thread->record_stack_base_and_size();
3387 main_thread->initialize_thread_local_storage();
3388
3389 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
3390
3391 if (!main_thread->set_as_starting_thread()) {
3392 vm_shutdown_during_initialization(
3393 "Failed necessary internal allocation. Out of swap space");
3394 delete main_thread;
3395 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3396 return JNI_ENOMEM;
3397 }
3398
3399 // Enable guard page *after* os::create_main_thread(), otherwise it would
3400 // crash Linux VM, see notes in os_linux.cpp.
3401 main_thread->create_stack_guard_pages();
3402
3403 // Initialize Java-Level synchronization subsystem
3404 ObjectMonitor::Initialize() ;
3405
3406 // Second phase of bootstrapping, VM is about entering multi-thread mode
3407 MemTracker::bootstrap_multi_thread();
3408
3409 // Initialize global modules
3410 jint status = init_globals();
3411 if (status != JNI_OK) {
3412 delete main_thread;
3413 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3414 return status;
3415 }
3416
3417 // Should be done after the heap is fully created
3418 main_thread->cache_global_variables();
3419
3420 HandleMark hm;
3421
3422 { MutexLocker mu(Threads_lock);
3423 Threads::add(main_thread);
3424 }
3425
3426 // Any JVMTI raw monitors entered in onload will transition into
3427 // real raw monitor. VM is setup enough here for raw monitor enter.
3428 JvmtiExport::transition_pending_onload_raw_monitors();
3429
3430 // Fully start NMT
3431 MemTracker::start();
3432
3433 // Create the VMThread
3434 { TraceTime timer("Start VMThread", TraceStartupTime);
3435 VMThread::create();
3436 Thread* vmthread = VMThread::vm_thread();
3437
3438 if (!os::create_thread(vmthread, os::vm_thread))
3439 vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
3440
3441 // Wait for the VM thread to become ready, and VMThread::run to initialize
3442 // Monitors can have spurious returns, must always check another state flag
3443 {
3444 MutexLocker ml(Notify_lock);
3445 os::start_thread(vmthread);
3446 while (vmthread->active_handles() == NULL) {
3447 Notify_lock->wait();
3448 }
3449 }
3450 }
3451
3452 assert (Universe::is_fully_initialized(), "not initialized");
3453 if (VerifyDuringStartup) {
3454 // Make sure we're starting with a clean slate.
3455 VM_Verify verify_op;
3456 VMThread::execute(&verify_op);
3457 }
3458
3459 EXCEPTION_MARK;
3460
3461 // At this point, the Universe is initialized, but we have not executed
3462 // any byte code. Now is a good time (the only time) to dump out the
3463 // internal state of the JVM for sharing.
3464 if (DumpSharedSpaces) {
3465 MetaspaceShared::preload_and_dump(CHECK_0);
3466 ShouldNotReachHere();
3467 }
3468
3469 // Always call even when there are not JVMTI environments yet, since environments
3470 // may be attached late and JVMTI must track phases of VM execution
3471 JvmtiExport::enter_start_phase();
3472
3473 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
3474 JvmtiExport::post_vm_start();
3475
3476 {
3477 TraceTime timer("Initialize java.lang classes", TraceStartupTime);
3478
3479 if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3480 create_vm_init_libraries();
3481 }
3482
3483 initialize_class(vmSymbols::java_lang_String(), CHECK_0);
3484
3485 if (AggressiveOpts) {
3486 {
3487 // Forcibly initialize java/util/HashMap and mutate the private
3488 // static final "frontCacheEnabled" field before we start creating instances
3489 #ifdef ASSERT
3490 Klass* tmp_k = SystemDictionary::find(vmSymbols::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3491 assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet");
3492 #endif
3493 Klass* k_o = SystemDictionary::resolve_or_null(vmSymbols::java_util_HashMap(), Handle(), Handle(), CHECK_0);
3494 KlassHandle k = KlassHandle(THREAD, k_o);
3495 guarantee(k.not_null(), "Must find java/util/HashMap");
3496 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3497 ik->initialize(CHECK_0);
3498 fieldDescriptor fd;
3499 // Possible we might not find this field; if so, don't break
3500 if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3501 k()->java_mirror()->bool_field_put(fd.offset(), true);
3502 }
3503 }
3504
3505 if (UseStringCache) {
3506 // Forcibly initialize java/lang/StringValue and mutate the private
3507 // static final "stringCacheEnabled" field before we start creating instances
3508 Klass* k_o = SystemDictionary::resolve_or_null(vmSymbols::java_lang_StringValue(), Handle(), Handle(), CHECK_0);
3509 // Possible that StringValue isn't present: if so, silently don't break
3510 if (k_o != NULL) {
3511 KlassHandle k = KlassHandle(THREAD, k_o);
3512 instanceKlassHandle ik = instanceKlassHandle(THREAD, k());
3513 ik->initialize(CHECK_0);
3514 fieldDescriptor fd;
3515 // Possible we might not find this field: if so, silently don't break
3516 if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) {
3517 k()->java_mirror()->bool_field_put(fd.offset(), true);
3518 }
3519 }
3520 }
3521 }
3522
3523 // Initialize java_lang.System (needed before creating the thread)
3524 initialize_class(vmSymbols::java_lang_System(), CHECK_0);
3525 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK_0);
3526 Handle thread_group = create_initial_thread_group(CHECK_0);
3527 Universe::set_main_thread_group(thread_group());
3528 initialize_class(vmSymbols::java_lang_Thread(), CHECK_0);
3529 oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
3530 main_thread->set_threadObj(thread_object);
3531 // Set thread status to running since main thread has
3532 // been started and running.
3533 java_lang_Thread::set_thread_status(thread_object,
3534 java_lang_Thread::RUNNABLE);
3535
3536 // The VM creates & returns objects of this class. Make sure it's initialized.
3537 initialize_class(vmSymbols::java_lang_Class(), CHECK_0);
3538
3539 // The VM preresolves methods to these classes. Make sure that they get initialized
3540 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK_0);
3541 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK_0);
3542 call_initializeSystemClass(CHECK_0);
3543
3544 // get the Java runtime name after java.lang.System is initialized
3545 JDK_Version::set_runtime_name(get_java_runtime_name(THREAD));
3546 JDK_Version::set_runtime_version(get_java_runtime_version(THREAD));
3547
3548 // an instance of OutOfMemory exception has been allocated earlier
3549 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK_0);
3550 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK_0);
3551 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK_0);
3552 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK_0);
3553 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK_0);
3554 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK_0);
3555 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK_0);
3556 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK_0);
3557 }
3558
3559 // See : bugid 4211085.
3560 // Background : the static initializer of java.lang.Compiler tries to read
3561 // property"java.compiler" and read & write property "java.vm.info".
3562 // When a security manager is installed through the command line
3563 // option "-Djava.security.manager", the above properties are not
3564 // readable and the static initializer for java.lang.Compiler fails
3565 // resulting in a NoClassDefFoundError. This can happen in any
3566 // user code which calls methods in java.lang.Compiler.
3567 // Hack : the hack is to pre-load and initialize this class, so that only
3568 // system domains are on the stack when the properties are read.
3569 // Currently even the AWT code has calls to methods in java.lang.Compiler.
3570 // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
3571 // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
3572 // read and write"java.vm.info" in the default policy file. See bugid 4211383
3573 // Once that is done, we should remove this hack.
3574 initialize_class(vmSymbols::java_lang_Compiler(), CHECK_0);
3575
3576 // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
3577 // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
3578 // compiler does not get loaded through java.lang.Compiler). "java -version" with the
3579 // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
3580 // This should also be taken out as soon as 4211383 gets fixed.
3581 reset_vm_info_property(CHECK_0);
3582
3583 quicken_jni_functions();
3584
3585 // Must be run after init_ft which initializes ft_enabled
3586 if (TRACE_INITIALIZE() != JNI_OK) {
3587 vm_exit_during_initialization("Failed to initialize tracing backend");
3588 }
3589
3590 // Set flag that basic initialization has completed. Used by exceptions and various
3591 // debug stuff, that does not work until all basic classes have been initialized.
3592 set_init_completed();
3593
3594 #ifndef USDT2
3595 HS_DTRACE_PROBE(hotspot, vm__init__end);
3596 #else /* USDT2 */
3597 HOTSPOT_VM_INIT_END();
3598 #endif /* USDT2 */
3599
3600 // record VM initialization completion time
3601 #if INCLUDE_MANAGEMENT
3602 Management::record_vm_init_completed();
3603 #endif // INCLUDE_MANAGEMENT
3604
3605 // Compute system loader. Note that this has to occur after set_init_completed, since
3606 // valid exceptions may be thrown in the process.
3607 // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
3608 // set_init_completed has just been called, causing exceptions not to be shortcut
3609 // anymore. We call vm_exit_during_initialization directly instead.
3610 SystemDictionary::compute_java_system_loader(THREAD);
3611 if (HAS_PENDING_EXCEPTION) {
3612 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3613 }
3614
3615 #if INCLUDE_ALL_GCS
3616 // Support for ConcurrentMarkSweep. This should be cleaned up
3617 // and better encapsulated. The ugly nested if test would go away
3618 // once things are properly refactored. XXX YSR
3619 if (UseConcMarkSweepGC || UseG1GC) {
3620 if (UseConcMarkSweepGC) {
3621 ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
3622 } else {
3623 ConcurrentMarkThread::makeSurrogateLockerThread(THREAD);
3624 }
3625 if (HAS_PENDING_EXCEPTION) {
3626 vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
3627 }
3628 }
3629 #endif // INCLUDE_ALL_GCS
3630
3631 // Always call even when there are not JVMTI environments yet, since environments
3632 // may be attached late and JVMTI must track phases of VM execution
3633 JvmtiExport::enter_live_phase();
3634
3635 // Signal Dispatcher needs to be started before VMInit event is posted
3636 os::signal_init();
3637
3638 // Start Attach Listener if +StartAttachListener or it can't be started lazily
3639 if (!DisableAttachMechanism) {
3640 if (StartAttachListener || AttachListener::init_at_startup()) {
3641 AttachListener::init();
3642 }
3643 }
3644
3645 // Launch -Xrun agents
3646 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
3647 // back-end can launch with -Xdebug -Xrunjdwp.
3648 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
3649 create_vm_init_libraries();
3650 }
3651
3652 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
3653 JvmtiExport::post_vm_initialized();
3654
3655 if (TRACE_START() != JNI_OK) {
3656 vm_exit_during_initialization("Failed to start tracing backend.");
3657 }
3658
3659 if (CleanChunkPoolAsync) {
3660 Chunk::start_chunk_pool_cleaner_task();
3661 }
3662
3663 // initialize compiler(s)
3664 #if defined(COMPILER1) || defined(COMPILER2) || defined(SHARK)
3665 CompileBroker::compilation_init();
3666 #endif
3667
3668 #if INCLUDE_MANAGEMENT
3669 Management::initialize(THREAD);
3670 #endif // INCLUDE_MANAGEMENT
3671
3672 if (HAS_PENDING_EXCEPTION) {
3673 // management agent fails to start possibly due to
3674 // configuration problem and is responsible for printing
3675 // stack trace if appropriate. Simply exit VM.
3676 vm_exit(1);
3677 }
3678
3679 if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
3680 if (Arguments::has_alloc_profile()) AllocationProfiler::engage();
3681 if (MemProfiling) MemProfiler::engage();
3682 StatSampler::engage();
3683 if (CheckJNICalls) JniPeriodicChecker::engage();
3684
3685 BiasedLocking::init();
3686
3687 if (JDK_Version::current().post_vm_init_hook_enabled()) {
3688 call_postVMInitHook(THREAD);
3689 // The Java side of PostVMInitHook.run must deal with all
3690 // exceptions and provide means of diagnosis.
3691 if (HAS_PENDING_EXCEPTION) {
3692 CLEAR_PENDING_EXCEPTION;
3693 }
3694 }
3695
3696 {
3697 MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
3698 // Make sure the watcher thread can be started by WatcherThread::start()
3699 // or by dynamic enrollment.
3700 WatcherThread::make_startable();
3701 // Start up the WatcherThread if there are any periodic tasks
3702 // NOTE: All PeriodicTasks should be registered by now. If they
3703 // aren't, late joiners might appear to start slowly (we might
3704 // take a while to process their first tick).
3705 if (PeriodicTask::num_tasks() > 0) {
3706 WatcherThread::start();
3707 }
3708 }
3709
3710 // Give os specific code one last chance to start
3711 os::init_3();
3712
3713 create_vm_timer.end();
3714 #ifdef ASSERT
3715 _vm_complete = true;
3716 #endif
3717 return JNI_OK;
3718 }
3719
3720 // type for the Agent_OnLoad and JVM_OnLoad entry points
3721 extern "C" {
3722 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
3723 }
3724 // Find a command line agent library and return its entry point for
3725 // -agentlib: -agentpath: -Xrun
3726 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
3727 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
3728 OnLoadEntry_t on_load_entry = NULL;
3729 void *library;
3730
3731 if (!agent->valid()) {
3732 char buffer[JVM_MAXPATHLEN];
3733 char ebuf[1024];
3734 const char *name = agent->name();
3735 const char *msg = "Could not find agent library ";
3736
3737 // First check to see if agent is statcally linked into executable
3738 if (os::findBuiltinAgent(agent, on_load_symbols, num_symbol_entries)) {
3739 library = agent->os_lib();
3740 } else if (agent->is_absolute_path()) {
3741 library = os::dll_load(name, ebuf, sizeof ebuf);
3742 if (library == NULL) {
3743 const char *sub_msg = " in absolute path, with error: ";
3744 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3745 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3746 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3747 // If we can't find the agent, exit.
3748 vm_exit_during_initialization(buf, NULL);
3749 FREE_C_HEAP_ARRAY(char, buf, mtThread);
3750 }
3751 } else {
3752 // Try to load the agent from the standard dll directory
3753 if (os::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
3754 name)) {
3755 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3756 }
3757 if (library == NULL) { // Try the local directory
3758 char ns[] = {0};
3759 if (os::dll_build_name(buffer, sizeof(buffer), ns, name)) {
3760 library = os::dll_load(buffer, ebuf, sizeof ebuf);
3761 }
3762 if (library == NULL) {
3763 const char *sub_msg = " on the library path, with error: ";
3764 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
3765 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
3766 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
3767 // If we can't find the agent, exit.
3768 vm_exit_during_initialization(buf, NULL);
3769 FREE_C_HEAP_ARRAY(char, buf, mtThread);
3770 }
3771 }
3772 }
3773 agent->set_os_lib(library);
3774 agent->set_valid();
3775 }
3776
3777 // Find the OnLoad function.
3778 on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, os::findAgentFunction(agent,
3779 false,
3780 on_load_symbols,
3781 num_symbol_entries));
3782 return on_load_entry;
3783 }
3784
3785 // Find the JVM_OnLoad entry point
3786 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
3787 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
3788 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3789 }
3790
3791 // Find the Agent_OnLoad entry point
3792 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
3793 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
3794 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
3795 }
3796
3797 // For backwards compatibility with -Xrun
3798 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
3799 // treated like -agentpath:
3800 // Must be called before agent libraries are created
3801 void Threads::convert_vm_init_libraries_to_agents() {
3802 AgentLibrary* agent;
3803 AgentLibrary* next;
3804
3805 for (agent = Arguments::libraries(); agent != NULL; agent = next) {
3806 next = agent->next(); // cache the next agent now as this agent may get moved off this list
3807 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3808
3809 // If there is an JVM_OnLoad function it will get called later,
3810 // otherwise see if there is an Agent_OnLoad
3811 if (on_load_entry == NULL) {
3812 on_load_entry = lookup_agent_on_load(agent);
3813 if (on_load_entry != NULL) {
3814 // switch it to the agent list -- so that Agent_OnLoad will be called,
3815 // JVM_OnLoad won't be attempted and Agent_OnUnload will
3816 Arguments::convert_library_to_agent(agent);
3817 } else {
3818 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
3819 }
3820 }
3821 }
3822 }
3823
3824 // Create agents for -agentlib: -agentpath: and converted -Xrun
3825 // Invokes Agent_OnLoad
3826 // Called very early -- before JavaThreads exist
3827 void Threads::create_vm_init_agents() {
3828 extern struct JavaVM_ main_vm;
3829 AgentLibrary* agent;
3830
3831 JvmtiExport::enter_onload_phase();
3832
3833 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3834 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
3835
3836 if (on_load_entry != NULL) {
3837 // Invoke the Agent_OnLoad function
3838 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3839 if (err != JNI_OK) {
3840 vm_exit_during_initialization("agent library failed to init", agent->name());
3841 }
3842 } else {
3843 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
3844 }
3845 }
3846 JvmtiExport::enter_primordial_phase();
3847 }
3848
3849 extern "C" {
3850 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
3851 }
3852
3853 void Threads::shutdown_vm_agents() {
3854 // Send any Agent_OnUnload notifications
3855 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
3856 size_t num_symbol_entries = sizeof(on_unload_symbols) / sizeof(char*);
3857 extern struct JavaVM_ main_vm;
3858 for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
3859
3860 // Find the Agent_OnUnload function.
3861 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
3862 os::findAgentFunction(agent,
3863 false,
3864 on_unload_symbols,
3865 num_symbol_entries));
3866
3867 // Invoke the Agent_OnUnload function
3868 if (unload_entry != NULL) {
3869 JavaThread* thread = JavaThread::current();
3870 ThreadToNativeFromVM ttn(thread);
3871 HandleMark hm(thread);
3872 (*unload_entry)(&main_vm);
3873 }
3874 }
3875 }
3876
3877 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
3878 // Invokes JVM_OnLoad
3879 void Threads::create_vm_init_libraries() {
3880 extern struct JavaVM_ main_vm;
3881 AgentLibrary* agent;
3882
3883 for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
3884 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
3885
3886 if (on_load_entry != NULL) {
3887 // Invoke the JVM_OnLoad function
3888 JavaThread* thread = JavaThread::current();
3889 ThreadToNativeFromVM ttn(thread);
3890 HandleMark hm(thread);
3891 jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
3892 if (err != JNI_OK) {
3893 vm_exit_during_initialization("-Xrun library failed to init", agent->name());
3894 }
3895 } else {
3896 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
3897 }
3898 }
3899 }
3900
3901 // Last thread running calls java.lang.Shutdown.shutdown()
3902 void JavaThread::invoke_shutdown_hooks() {
3903 HandleMark hm(this);
3904
3905 // We could get here with a pending exception, if so clear it now.
3906 if (this->has_pending_exception()) {
3907 this->clear_pending_exception();
3908 }
3909
3910 EXCEPTION_MARK;
3911 Klass* k =
3912 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
3913 THREAD);
3914 if (k != NULL) {
3915 // SystemDictionary::resolve_or_null will return null if there was
3916 // an exception. If we cannot load the Shutdown class, just don't
3917 // call Shutdown.shutdown() at all. This will mean the shutdown hooks
3918 // and finalizers (if runFinalizersOnExit is set) won't be run.
3919 // Note that if a shutdown hook was registered or runFinalizersOnExit
3920 // was called, the Shutdown class would have already been loaded
3921 // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
3922 instanceKlassHandle shutdown_klass (THREAD, k);
3923 JavaValue result(T_VOID);
3924 JavaCalls::call_static(&result,
3925 shutdown_klass,
3926 vmSymbols::shutdown_method_name(),
3927 vmSymbols::void_method_signature(),
3928 THREAD);
3929 }
3930 CLEAR_PENDING_EXCEPTION;
3931 }
3932
3933 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
3934 // the program falls off the end of main(). Another VM exit path is through
3935 // vm_exit() when the program calls System.exit() to return a value or when
3936 // there is a serious error in VM. The two shutdown paths are not exactly
3937 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
3938 // and VM_Exit op at VM level.
3939 //
3940 // Shutdown sequence:
3941 // + Shutdown native memory tracking if it is on
3942 // + Wait until we are the last non-daemon thread to execute
3943 // <-- every thing is still working at this moment -->
3944 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
3945 // shutdown hooks, run finalizers if finalization-on-exit
3946 // + Call before_exit(), prepare for VM exit
3947 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
3948 // currently the only user of this mechanism is File.deleteOnExit())
3949 // > stop flat profiler, StatSampler, watcher thread, CMS threads,
3950 // post thread end and vm death events to JVMTI,
3951 // stop signal thread
3952 // + Call JavaThread::exit(), it will:
3953 // > release JNI handle blocks, remove stack guard pages
3954 // > remove this thread from Threads list
3955 // <-- no more Java code from this thread after this point -->
3956 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
3957 // the compiler threads at safepoint
3958 // <-- do not use anything that could get blocked by Safepoint -->
3959 // + Disable tracing at JNI/JVM barriers
3960 // + Set _vm_exited flag for threads that are still running native code
3961 // + Delete this thread
3962 // + Call exit_globals()
3963 // > deletes tty
3964 // > deletes PerfMemory resources
3965 // + Return to caller
3966
3967 bool Threads::destroy_vm() {
3968 JavaThread* thread = JavaThread::current();
3969
3970 #ifdef ASSERT
3971 _vm_complete = false;
3972 #endif
3973 // Wait until we are the last non-daemon thread to execute
3974 { MutexLocker nu(Threads_lock);
3975 while (Threads::number_of_non_daemon_threads() > 1 )
3976 // This wait should make safepoint checks, wait without a timeout,
3977 // and wait as a suspend-equivalent condition.
3978 //
3979 // Note: If the FlatProfiler is running and this thread is waiting
3980 // for another non-daemon thread to finish, then the FlatProfiler
3981 // is waiting for the external suspend request on this thread to
3982 // complete. wait_for_ext_suspend_completion() will eventually
3983 // timeout, but that takes time. Making this wait a suspend-
3984 // equivalent condition solves that timeout problem.
3985 //
3986 Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
3987 Mutex::_as_suspend_equivalent_flag);
3988 }
3989
3990 // Hang forever on exit if we are reporting an error.
3991 if (ShowMessageBoxOnError && is_error_reported()) {
3992 os::infinite_sleep();
3993 }
3994 os::wait_for_keypress_at_exit();
3995
3996 if (JDK_Version::is_jdk12x_version()) {
3997 // We are the last thread running, so check if finalizers should be run.
3998 // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
3999 HandleMark rm(thread);
4000 Universe::run_finalizers_on_exit();
4001 } else {
4002 // run Java level shutdown hooks
4003 thread->invoke_shutdown_hooks();
4004 }
4005
4006 before_exit(thread);
4007
4008 thread->exit(true);
4009
4010 // Stop VM thread.
4011 {
4012 // 4945125 The vm thread comes to a safepoint during exit.
4013 // GC vm_operations can get caught at the safepoint, and the
4014 // heap is unparseable if they are caught. Grab the Heap_lock
4015 // to prevent this. The GC vm_operations will not be able to
4016 // queue until after the vm thread is dead.
4017 // After this point, we'll never emerge out of the safepoint before
4018 // the VM exits, so concurrent GC threads do not need to be explicitly
4019 // stopped; they remain inactive until the process exits.
4020 // Note: some concurrent G1 threads may be running during a safepoint,
4021 // but these will not be accessing the heap, just some G1-specific side
4022 // data structures that are not accessed by any other threads but them
4023 // after this point in a terminal safepoint.
4024
4025 MutexLocker ml(Heap_lock);
4026
4027 VMThread::wait_for_vm_thread_exit();
4028 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
4029 VMThread::destroy();
4030 }
4031
4032 // clean up ideal graph printers
4033 #if defined(COMPILER2) && !defined(PRODUCT)
4034 IdealGraphPrinter::clean_up();
4035 #endif
4036
4037 // Now, all Java threads are gone except daemon threads. Daemon threads
4038 // running Java code or in VM are stopped by the Safepoint. However,
4039 // daemon threads executing native code are still running. But they
4040 // will be stopped at native=>Java/VM barriers. Note that we can't
4041 // simply kill or suspend them, as it is inherently deadlock-prone.
4042
4043 #ifndef PRODUCT
4044 // disable function tracing at JNI/JVM barriers
4045 TraceJNICalls = false;
4046 TraceJVMCalls = false;
4047 TraceRuntimeCalls = false;
4048 #endif
4049
4050 VM_Exit::set_vm_exited();
4051
4052 notify_vm_shutdown();
4053
4054 delete thread;
4055
4056 // exit_globals() will delete tty
4057 exit_globals();
4058
4059 return true;
4060 }
4061
4062
4063 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
4064 if (version == JNI_VERSION_1_1) return JNI_TRUE;
4065 return is_supported_jni_version(version);
4066 }
4067
4068
4069 jboolean Threads::is_supported_jni_version(jint version) {
4070 if (version == JNI_VERSION_1_2) return JNI_TRUE;
4071 if (version == JNI_VERSION_1_4) return JNI_TRUE;
4072 if (version == JNI_VERSION_1_6) return JNI_TRUE;
4073 if (version == JNI_VERSION_1_8) return JNI_TRUE;
4074 return JNI_FALSE;
4075 }
4076
4077
4078 void Threads::add(JavaThread* p, bool force_daemon) {
4079 // The threads lock must be owned at this point
4080 assert_locked_or_safepoint(Threads_lock);
4081
4082 // See the comment for this method in thread.hpp for its purpose and
4083 // why it is called here.
4084 p->initialize_queues();
4085 p->set_next(_thread_list);
4086 _thread_list = p;
4087 _number_of_threads++;
4088 oop threadObj = p->threadObj();
4089 bool daemon = true;
4090 // Bootstrapping problem: threadObj can be null for initial
4091 // JavaThread (or for threads attached via JNI)
4092 if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
4093 _number_of_non_daemon_threads++;
4094 daemon = false;
4095 }
4096
4097 p->set_safepoint_visible(true);
4098
4099 ThreadService::add_thread(p, daemon);
4100
4101 // Possible GC point.
4102 Events::log(p, "Thread added: " INTPTR_FORMAT, p);
4103 }
4104
4105 void Threads::remove(JavaThread* p) {
4106 // Extra scope needed for Thread_lock, so we can check
4107 // that we do not remove thread without safepoint code notice
4108 { MutexLocker ml(Threads_lock);
4109
4110 assert(includes(p), "p must be present");
4111
4112 JavaThread* current = _thread_list;
4113 JavaThread* prev = NULL;
4114
4115 while (current != p) {
4116 prev = current;
4117 current = current->next();
4118 }
4119
4120 if (prev) {
4121 prev->set_next(current->next());
4122 } else {
4123 _thread_list = p->next();
4124 }
4125 _number_of_threads--;
4126 oop threadObj = p->threadObj();
4127 bool daemon = true;
4128 if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
4129 _number_of_non_daemon_threads--;
4130 daemon = false;
4131
4132 // Only one thread left, do a notify on the Threads_lock so a thread waiting
4133 // on destroy_vm will wake up.
4134 if (number_of_non_daemon_threads() == 1)
4135 Threads_lock->notify_all();
4136 }
4137 ThreadService::remove_thread(p, daemon);
4138
4139 // Make sure that safepoint code disregard this thread. This is needed since
4140 // the thread might mess around with locks after this point. This can cause it
4141 // to do callbacks into the safepoint code. However, the safepoint code is not aware
4142 // of this thread since it is removed from the queue.
4143 p->set_terminated_value();
4144
4145 // Now, this thread is not visible to safepoint
4146 p->set_safepoint_visible(false);
4147 // once the thread becomes safepoint invisible, we can not use its per-thread
4148 // recorder. And Threads::do_threads() no longer walks this thread, so we have
4149 // to release its per-thread recorder here.
4150 MemTracker::thread_exiting(p);
4151 } // unlock Threads_lock
4152
4153 // Since Events::log uses a lock, we grab it outside the Threads_lock
4154 Events::log(p, "Thread exited: " INTPTR_FORMAT, p);
4155 }
4156
4157 // Threads_lock must be held when this is called (or must be called during a safepoint)
4158 bool Threads::includes(JavaThread* p) {
4159 assert(Threads_lock->is_locked(), "sanity check");
4160 ALL_JAVA_THREADS(q) {
4161 if (q == p ) {
4162 return true;
4163 }
4164 }
4165 return false;
4166 }
4167
4168 // Operations on the Threads list for GC. These are not explicitly locked,
4169 // but the garbage collector must provide a safe context for them to run.
4170 // In particular, these things should never be called when the Threads_lock
4171 // is held by some other thread. (Note: the Safepoint abstraction also
4172 // uses the Threads_lock to gurantee this property. It also makes sure that
4173 // all threads gets blocked when exiting or starting).
4174
4175 void Threads::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) {
4176 ALL_JAVA_THREADS(p) {
4177 p->oops_do(f, cld_f, cf);
4178 }
4179 VMThread::vm_thread()->oops_do(f, cld_f, cf);
4180 }
4181
4182 void Threads::possibly_parallel_oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) {
4183 // Introduce a mechanism allowing parallel threads to claim threads as
4184 // root groups. Overhead should be small enough to use all the time,
4185 // even in sequential code.
4186 SharedHeap* sh = SharedHeap::heap();
4187 // Cannot yet substitute active_workers for n_par_threads
4188 // because of G1CollectedHeap::verify() use of
4189 // SharedHeap::process_strong_roots(). n_par_threads == 0 will
4190 // turn off parallelism in process_strong_roots while active_workers
4191 // is being used for parallelism elsewhere.
4192 bool is_par = sh->n_par_threads() > 0;
4193 assert(!is_par ||
4194 (SharedHeap::heap()->n_par_threads() ==
4195 SharedHeap::heap()->workers()->active_workers()), "Mismatch");
4196 int cp = SharedHeap::heap()->strong_roots_parity();
4197 ALL_JAVA_THREADS(p) {
4198 if (p->claim_oops_do(is_par, cp)) {
4199 p->oops_do(f, cld_f, cf);
4200 }
4201 }
4202 VMThread* vmt = VMThread::vm_thread();
4203 if (vmt->claim_oops_do(is_par, cp)) {
4204 vmt->oops_do(f, cld_f, cf);
4205 }
4206 }
4207
4208 #if INCLUDE_ALL_GCS
4209 // Used by ParallelScavenge
4210 void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
4211 ALL_JAVA_THREADS(p) {
4212 q->enqueue(new ThreadRootsTask(p));
4213 }
4214 q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
4215 }
4216
4217 // Used by Parallel Old
4218 void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
4219 ALL_JAVA_THREADS(p) {
4220 q->enqueue(new ThreadRootsMarkingTask(p));
4221 }
4222 q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
4223 }
4224 #endif // INCLUDE_ALL_GCS
4225
4226 void Threads::nmethods_do(CodeBlobClosure* cf) {
4227 ALL_JAVA_THREADS(p) {
4228 p->nmethods_do(cf);
4229 }
4230 VMThread::vm_thread()->nmethods_do(cf);
4231 }
4232
4233 void Threads::metadata_do(void f(Metadata*)) {
4234 ALL_JAVA_THREADS(p) {
4235 p->metadata_do(f);
4236 }
4237 }
4238
4239 void Threads::gc_epilogue() {
4240 ALL_JAVA_THREADS(p) {
4241 p->gc_epilogue();
4242 }
4243 }
4244
4245 void Threads::gc_prologue() {
4246 ALL_JAVA_THREADS(p) {
4247 p->gc_prologue();
4248 }
4249 }
4250
4251 void Threads::deoptimized_wrt_marked_nmethods() {
4252 ALL_JAVA_THREADS(p) {
4253 p->deoptimized_wrt_marked_nmethods();
4254 }
4255 }
4256
4257
4258 // Get count Java threads that are waiting to enter the specified monitor.
4259 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
4260 address monitor, bool doLock) {
4261 assert(doLock || SafepointSynchronize::is_at_safepoint(),
4262 "must grab Threads_lock or be at safepoint");
4263 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
4264
4265 int i = 0;
4266 {
4267 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4268 ALL_JAVA_THREADS(p) {
4269 if (p->is_Compiler_thread()) continue;
4270
4271 address pending = (address)p->current_pending_monitor();
4272 if (pending == monitor) { // found a match
4273 if (i < count) result->append(p); // save the first count matches
4274 i++;
4275 }
4276 }
4277 }
4278 return result;
4279 }
4280
4281
4282 JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
4283 assert(doLock ||
4284 Threads_lock->owned_by_self() ||
4285 SafepointSynchronize::is_at_safepoint(),
4286 "must grab Threads_lock or be at safepoint");
4287
4288 // NULL owner means not locked so we can skip the search
4289 if (owner == NULL) return NULL;
4290
4291 {
4292 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4293 ALL_JAVA_THREADS(p) {
4294 // first, see if owner is the address of a Java thread
4295 if (owner == (address)p) return p;
4296 }
4297 }
4298 // Cannot assert on lack of success here since this function may be
4299 // used by code that is trying to report useful problem information
4300 // like deadlock detection.
4301 if (UseHeavyMonitors) return NULL;
4302
4303 //
4304 // If we didn't find a matching Java thread and we didn't force use of
4305 // heavyweight monitors, then the owner is the stack address of the
4306 // Lock Word in the owning Java thread's stack.
4307 //
4308 JavaThread* the_owner = NULL;
4309 {
4310 MutexLockerEx ml(doLock ? Threads_lock : NULL);
4311 ALL_JAVA_THREADS(q) {
4312 if (q->is_lock_owned(owner)) {
4313 the_owner = q;
4314 break;
4315 }
4316 }
4317 }
4318 // cannot assert on lack of success here; see above comment
4319 return the_owner;
4320 }
4321
4322 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
4323 void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
4324 char buf[32];
4325 st->print_cr(os::local_time_string(buf, sizeof(buf)));
4326
4327 st->print_cr("Full thread dump %s (%s %s):",
4328 Abstract_VM_Version::vm_name(),
4329 Abstract_VM_Version::vm_release(),
4330 Abstract_VM_Version::vm_info_string()
4331 );
4332 st->cr();
4333
4334 #if INCLUDE_ALL_GCS
4335 // Dump concurrent locks
4336 ConcurrentLocksDump concurrent_locks;
4337 if (print_concurrent_locks) {
4338 concurrent_locks.dump_at_safepoint();
4339 }
4340 #endif // INCLUDE_ALL_GCS
4341
4342 ALL_JAVA_THREADS(p) {
4343 ResourceMark rm;
4344 p->print_on(st);
4345 if (print_stacks) {
4346 if (internal_format) {
4347 p->trace_stack();
4348 } else {
4349 p->print_stack_on(st);
4350 }
4351 }
4352 st->cr();
4353 #if INCLUDE_ALL_GCS
4354 if (print_concurrent_locks) {
4355 concurrent_locks.print_locks_on(p, st);
4356 }
4357 #endif // INCLUDE_ALL_GCS
4358 }
4359
4360 VMThread::vm_thread()->print_on(st);
4361 st->cr();
4362 Universe::heap()->print_gc_threads_on(st);
4363 WatcherThread* wt = WatcherThread::watcher_thread();
4364 if (wt != NULL) {
4365 wt->print_on(st);
4366 st->cr();
4367 }
4368 CompileBroker::print_compiler_threads_on(st);
4369 st->flush();
4370 }
4371
4372 // Threads::print_on_error() is called by fatal error handler. It's possible
4373 // that VM is not at safepoint and/or current thread is inside signal handler.
4374 // Don't print stack trace, as the stack may not be walkable. Don't allocate
4375 // memory (even in resource area), it might deadlock the error handler.
4376 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
4377 bool found_current = false;
4378 st->print_cr("Java Threads: ( => current thread )");
4379 ALL_JAVA_THREADS(thread) {
4380 bool is_current = (current == thread);
4381 found_current = found_current || is_current;
4382
4383 st->print("%s", is_current ? "=>" : " ");
4384
4385 st->print(PTR_FORMAT, thread);
4386 st->print(" ");
4387 thread->print_on_error(st, buf, buflen);
4388 st->cr();
4389 }
4390 st->cr();
4391
4392 st->print_cr("Other Threads:");
4393 if (VMThread::vm_thread()) {
4394 bool is_current = (current == VMThread::vm_thread());
4395 found_current = found_current || is_current;
4396 st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
4397
4398 st->print(PTR_FORMAT, VMThread::vm_thread());
4399 st->print(" ");
4400 VMThread::vm_thread()->print_on_error(st, buf, buflen);
4401 st->cr();
4402 }
4403 WatcherThread* wt = WatcherThread::watcher_thread();
4404 if (wt != NULL) {
4405 bool is_current = (current == wt);
4406 found_current = found_current || is_current;
4407 st->print("%s", is_current ? "=>" : " ");
4408
4409 st->print(PTR_FORMAT, wt);
4410 st->print(" ");
4411 wt->print_on_error(st, buf, buflen);
4412 st->cr();
4413 }
4414 if (!found_current) {
4415 st->cr();
4416 st->print("=>" PTR_FORMAT " (exited) ", current);
4417 current->print_on_error(st, buf, buflen);
4418 st->cr();
4419 }
4420 }
4421
4422 // Internal SpinLock and Mutex
4423 // Based on ParkEvent
4424
4425 // Ad-hoc mutual exclusion primitives: SpinLock and Mux
4426 //
4427 // We employ SpinLocks _only for low-contention, fixed-length
4428 // short-duration critical sections where we're concerned
4429 // about native mutex_t or HotSpot Mutex:: latency.
4430 // The mux construct provides a spin-then-block mutual exclusion
4431 // mechanism.
4432 //
4433 // Testing has shown that contention on the ListLock guarding gFreeList
4434 // is common. If we implement ListLock as a simple SpinLock it's common
4435 // for the JVM to devolve to yielding with little progress. This is true
4436 // despite the fact that the critical sections protected by ListLock are
4437 // extremely short.
4438 //
4439 // TODO-FIXME: ListLock should be of type SpinLock.
4440 // We should make this a 1st-class type, integrated into the lock
4441 // hierarchy as leaf-locks. Critically, the SpinLock structure
4442 // should have sufficient padding to avoid false-sharing and excessive
4443 // cache-coherency traffic.
4444
4445
4446 typedef volatile int SpinLockT ;
4447
4448 void Thread::SpinAcquire (volatile int * adr, const char * LockName) {
4449 if (Atomic::cmpxchg (1, adr, 0) == 0) {
4450 return ; // normal fast-path return
4451 }
4452
4453 // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
4454 TEVENT (SpinAcquire - ctx) ;
4455 int ctr = 0 ;
4456 int Yields = 0 ;
4457 for (;;) {
4458 while (*adr != 0) {
4459 ++ctr ;
4460 if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
4461 if (Yields > 5) {
4462 // Consider using a simple NakedSleep() instead.
4463 // Then SpinAcquire could be called by non-JVM threads
4464 Thread::current()->_ParkEvent->park(1) ;
4465 } else {
4466 os::NakedYield() ;
4467 ++Yields ;
4468 }
4469 } else {
4470 SpinPause() ;
4471 }
4472 }
4473 if (Atomic::cmpxchg (1, adr, 0) == 0) return ;
4474 }
4475 }
4476
4477 void Thread::SpinRelease (volatile int * adr) {
4478 assert (*adr != 0, "invariant") ;
4479 OrderAccess::fence() ; // guarantee at least release consistency.
4480 // Roach-motel semantics.
4481 // It's safe if subsequent LDs and STs float "up" into the critical section,
4482 // but prior LDs and STs within the critical section can't be allowed
4483 // to reorder or float past the ST that releases the lock.
4484 *adr = 0 ;
4485 }
4486
4487 // muxAcquire and muxRelease:
4488 //
4489 // * muxAcquire and muxRelease support a single-word lock-word construct.
4490 // The LSB of the word is set IFF the lock is held.
4491 // The remainder of the word points to the head of a singly-linked list
4492 // of threads blocked on the lock.
4493 //
4494 // * The current implementation of muxAcquire-muxRelease uses its own
4495 // dedicated Thread._MuxEvent instance. If we're interested in
4496 // minimizing the peak number of extant ParkEvent instances then
4497 // we could eliminate _MuxEvent and "borrow" _ParkEvent as long
4498 // as certain invariants were satisfied. Specifically, care would need
4499 // to be taken with regards to consuming unpark() "permits".
4500 // A safe rule of thumb is that a thread would never call muxAcquire()
4501 // if it's enqueued (cxq, EntryList, WaitList, etc) and will subsequently
4502 // park(). Otherwise the _ParkEvent park() operation in muxAcquire() could
4503 // consume an unpark() permit intended for monitorenter, for instance.
4504 // One way around this would be to widen the restricted-range semaphore
4505 // implemented in park(). Another alternative would be to provide
4506 // multiple instances of the PlatformEvent() for each thread. One
4507 // instance would be dedicated to muxAcquire-muxRelease, for instance.
4508 //
4509 // * Usage:
4510 // -- Only as leaf locks
4511 // -- for short-term locking only as muxAcquire does not perform
4512 // thread state transitions.
4513 //
4514 // Alternatives:
4515 // * We could implement muxAcquire and muxRelease with MCS or CLH locks
4516 // but with parking or spin-then-park instead of pure spinning.
4517 // * Use Taura-Oyama-Yonenzawa locks.
4518 // * It's possible to construct a 1-0 lock if we encode the lockword as
4519 // (List,LockByte). Acquire will CAS the full lockword while Release
4520 // will STB 0 into the LockByte. The 1-0 scheme admits stranding, so
4521 // acquiring threads use timers (ParkTimed) to detect and recover from
4522 // the stranding window. Thread/Node structures must be aligned on 256-byte
4523 // boundaries by using placement-new.
4524 // * Augment MCS with advisory back-link fields maintained with CAS().
4525 // Pictorially: LockWord -> T1 <-> T2 <-> T3 <-> ... <-> Tn <-> Owner.
4526 // The validity of the backlinks must be ratified before we trust the value.
4527 // If the backlinks are invalid the exiting thread must back-track through the
4528 // the forward links, which are always trustworthy.
4529 // * Add a successor indication. The LockWord is currently encoded as
4530 // (List, LOCKBIT:1). We could also add a SUCCBIT or an explicit _succ variable
4531 // to provide the usual futile-wakeup optimization.
4532 // See RTStt for details.
4533 // * Consider schedctl.sc_nopreempt to cover the critical section.
4534 //
4535
4536
4537 typedef volatile intptr_t MutexT ; // Mux Lock-word
4538 enum MuxBits { LOCKBIT = 1 } ;
4539
4540 void Thread::muxAcquire (volatile intptr_t * Lock, const char * LockName) {
4541 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
4542 if (w == 0) return ;
4543 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4544 return ;
4545 }
4546
4547 TEVENT (muxAcquire - Contention) ;
4548 ParkEvent * const Self = Thread::current()->_MuxEvent ;
4549 assert ((intptr_t(Self) & LOCKBIT) == 0, "invariant") ;
4550 for (;;) {
4551 int its = (os::is_MP() ? 100 : 0) + 1 ;
4552
4553 // Optional spin phase: spin-then-park strategy
4554 while (--its >= 0) {
4555 w = *Lock ;
4556 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4557 return ;
4558 }
4559 }
4560
4561 Self->reset() ;
4562 Self->OnList = intptr_t(Lock) ;
4563 // The following fence() isn't _strictly necessary as the subsequent
4564 // CAS() both serializes execution and ratifies the fetched *Lock value.
4565 OrderAccess::fence();
4566 for (;;) {
4567 w = *Lock ;
4568 if ((w & LOCKBIT) == 0) {
4569 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4570 Self->OnList = 0 ; // hygiene - allows stronger asserts
4571 return ;
4572 }
4573 continue ; // Interference -- *Lock changed -- Just retry
4574 }
4575 assert (w & LOCKBIT, "invariant") ;
4576 Self->ListNext = (ParkEvent *) (w & ~LOCKBIT );
4577 if (Atomic::cmpxchg_ptr (intptr_t(Self)|LOCKBIT, Lock, w) == w) break ;
4578 }
4579
4580 while (Self->OnList != 0) {
4581 Self->park() ;
4582 }
4583 }
4584 }
4585
4586 void Thread::muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) {
4587 intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
4588 if (w == 0) return ;
4589 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4590 return ;
4591 }
4592
4593 TEVENT (muxAcquire - Contention) ;
4594 ParkEvent * ReleaseAfter = NULL ;
4595 if (ev == NULL) {
4596 ev = ReleaseAfter = ParkEvent::Allocate (NULL) ;
4597 }
4598 assert ((intptr_t(ev) & LOCKBIT) == 0, "invariant") ;
4599 for (;;) {
4600 guarantee (ev->OnList == 0, "invariant") ;
4601 int its = (os::is_MP() ? 100 : 0) + 1 ;
4602
4603 // Optional spin phase: spin-then-park strategy
4604 while (--its >= 0) {
4605 w = *Lock ;
4606 if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4607 if (ReleaseAfter != NULL) {
4608 ParkEvent::Release (ReleaseAfter) ;
4609 }
4610 return ;
4611 }
4612 }
4613
4614 ev->reset() ;
4615 ev->OnList = intptr_t(Lock) ;
4616 // The following fence() isn't _strictly necessary as the subsequent
4617 // CAS() both serializes execution and ratifies the fetched *Lock value.
4618 OrderAccess::fence();
4619 for (;;) {
4620 w = *Lock ;
4621 if ((w & LOCKBIT) == 0) {
4622 if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
4623 ev->OnList = 0 ;
4624 // We call ::Release while holding the outer lock, thus
4625 // artificially lengthening the critical section.
4626 // Consider deferring the ::Release() until the subsequent unlock(),
4627 // after we've dropped the outer lock.
4628 if (ReleaseAfter != NULL) {
4629 ParkEvent::Release (ReleaseAfter) ;
4630 }
4631 return ;
4632 }
4633 continue ; // Interference -- *Lock changed -- Just retry
4634 }
4635 assert (w & LOCKBIT, "invariant") ;
4636 ev->ListNext = (ParkEvent *) (w & ~LOCKBIT );
4637 if (Atomic::cmpxchg_ptr (intptr_t(ev)|LOCKBIT, Lock, w) == w) break ;
4638 }
4639
4640 while (ev->OnList != 0) {
4641 ev->park() ;
4642 }
4643 }
4644 }
4645
4646 // Release() must extract a successor from the list and then wake that thread.
4647 // It can "pop" the front of the list or use a detach-modify-reattach (DMR) scheme
4648 // similar to that used by ParkEvent::Allocate() and ::Release(). DMR-based
4649 // Release() would :
4650 // (A) CAS() or swap() null to *Lock, releasing the lock and detaching the list.
4651 // (B) Extract a successor from the private list "in-hand"
4652 // (C) attempt to CAS() the residual back into *Lock over null.
4653 // If there were any newly arrived threads and the CAS() would fail.
4654 // In that case Release() would detach the RATs, re-merge the list in-hand
4655 // with the RATs and repeat as needed. Alternately, Release() might
4656 // detach and extract a successor, but then pass the residual list to the wakee.
4657 // The wakee would be responsible for reattaching and remerging before it
4658 // competed for the lock.
4659 //
4660 // Both "pop" and DMR are immune from ABA corruption -- there can be
4661 // multiple concurrent pushers, but only one popper or detacher.
4662 // This implementation pops from the head of the list. This is unfair,
4663 // but tends to provide excellent throughput as hot threads remain hot.
4664 // (We wake recently run threads first).
4665
4666 void Thread::muxRelease (volatile intptr_t * Lock) {
4667 for (;;) {
4668 const intptr_t w = Atomic::cmpxchg_ptr (0, Lock, LOCKBIT) ;
4669 assert (w & LOCKBIT, "invariant") ;
4670 if (w == LOCKBIT) return ;
4671 ParkEvent * List = (ParkEvent *) (w & ~LOCKBIT) ;
4672 assert (List != NULL, "invariant") ;
4673 assert (List->OnList == intptr_t(Lock), "invariant") ;
4674 ParkEvent * nxt = List->ListNext ;
4675
4676 // The following CAS() releases the lock and pops the head element.
4677 if (Atomic::cmpxchg_ptr (intptr_t(nxt), Lock, w) != w) {
4678 continue ;
4679 }
4680 List->OnList = 0 ;
4681 OrderAccess::fence() ;
4682 List->unpark () ;
4683 return ;
4684 }
4685 }
4686
4687
4688 void Threads::verify() {
4689 ALL_JAVA_THREADS(p) {
4690 p->verify();
4691 }
4692 VMThread* thread = VMThread::vm_thread();
4693 if (thread != NULL) thread->verify();
4694 }